Wednesday, July 6, 2016

Making Dromaeosaurids Nasty Again Part III: Life Appearance - Dapper or Deranged?

Skeksis (singular and plural) Antagonists from Jim Henson's 1982 film The Dark Crystal. Concept artist Brian Froud conceived as "part reptile, part predatory bird, part dragon".

Appearance (from wikipedia):

The Skeksis are tall bipeds combining avian and reptilian characteristics. They wear elaborate but threadbare robes of lace, velvet, and brocade which apparently keep the skeksis' constantly decomposing bodies intact and make them look larger and more intimidating. Their heads are beaked like a vulture's but simultaneously sporting curved fangs. They have enlarged bellies and long reptilian tails, as well as curved quills on their backs. They have two pairs of arms but only one functional the other reduced... despite their frail appearance they are powerful creatures.

It should be no great revelation that this post will serve as the most subjective and probably therefore most controversial in this series. Experience in electing novel soft tissue structures in T. rex and Smilodon has  taught me that much...

It should also come as no surprise to readers that I am no great fan of dapper dromaeosaurids - a look that has come into vogue in recent years.

Dapper /'dapper/ adjective (typically of a man) neat and trim of dress, appearance, or bearing.

Deinonycus antirrhopus credit John Conway CC3.0

How did this look evolve? It is not too hard to trace a lineage of inspiration from Gregory S. Paul who retooled dromaeosaurids as feathered and decidedly bird like to John Conway who took a lot from Paul's look and made these animals even more birdy to Emily Willoughby one of the leading contemporary dromaeosaurid paleoartists whom has greatly inspired the dominant ground hawk look.

Acheroraptor credit Emily WilloughbyCC3.0
A commonality in all three of these artist's look is the clean cut juncture on the facial region separating feathered from non-feathered parts. This clean cut visage, almost always combined with an attractive feathery countenance lifted from a modern bird of prey (red tailed hawks and peregrine falcons are common suspects). A look that has been consistently aped and imbued itself into the dominate appearance of these animals in paleoart.

Peregrine Falcon credit Magnus Manske CC2.0

Gregory S. Paul hypothesized a "proto-beak" around the mouth of his dromaeosaurids and other maniraptorans. Basically an area free of integument and slightly cornified. See here and here. Essentially it was an inference made on the perceived - and correct - relatedness to modern birds.

The problem is that we do not have any evidence of a proto-beak in dromaeosaurids or any predatory maniraptorans at all for that matter. Nothing, nada, nunca. Nor do we have any evidence of the type of clean cut juncture depicted by Conway & Willoughby which has influenced current depictions.

Mathew Martyniuk discussed this seldom mentioned meme in an excellent post The First Feathered Dinosaurs (In Art):

"Paul essentially invented the latter meme (half feathered faces) in an attempt to make his theropods look more bird like (by suggesting a sort of beak), and while this was his own speculation, many later artists ran with it, including in early drawings of Sinosauropteryx."

While Conway's and Willoughby's renderings do not necessarily imply the sort of "proto-beak" structure that Paul hypothesized both of these artists kept the clean cut dapper "featherline" which Paul used demarcating a solid break from the feathered region of the head and the bitey jaw region. This trope has imbued itself into countless depictions of dromaeosaurids since, to the point that it is in many ways the de-facto way to depict the heads of these animals in many people's minds. Just remember - if you chose to depict dromaesaurs this way you are merely inheriting a trope that has no basis in evidence of either a proto-beak or a defined juncture between feathers and non-feathery covering on the heads of these animals. Not saying it is impossible that some dromies did not have such a juncture just that it is based on a hypothesis of a proto-beak which has not been borne out evidence wise but remains with us as an attractive speculation.

Indeed feathers covering the entirety of the head (except maybe the nostrils left open ala mammal noses) is what might be the more parsimonious interpretation as suggested by Sinornithosaurus and Zhenyuanlong. With no evidence of a proto-beak in these animals there is no reason to assume feathers did not go all the way to the oral region.

Sinornithosaurus 'Dave' credit DinoGuy2 CC1.0
This actually opens the doors for a lot more play as goes the facial appearance of these animals. As it should be, because we should not expect a lineage of animals that evolved and lived in diverse conditions for over 100 million years to all look a like. Everywhere from fully feathered to yes, naked skin, or in between.

"Go Away" by Lucas-Attwell w/permission Tsaagan mangas. deviantart
You know I loves me some vulturine inspired dromies. I really like how the tail display, arm-wings, contrasting white/dark colors, and jaw are all used together in threat display. As I argued in my last post there is at least as much - if not more - to glean from vultures as analogues to many dromaeosaurids as there is from raptorial accipterids. Also note that the feathers are plumaceous like in an ostrich not the stiff venaceous feathers we have often seen in paleoart.

Tsaagan. credit Matt Martyniuk CC2.5

I am a little surprised at the blowback I receive in electing naked headed, gnarly faced, caruncle ridden dromaeosaurs as a likely look for many of these animals. But why not? I am fully willing to concede my bias for ugly, uncouth, goblin looking critters duh.... I wear my inspirations on my sleeves baked in bong hit residue, blotter acid, splatter films, and swedish death metal. That does not mean I am in fact wholly wrong. More to the point, I would suggest others are less open than I am in conceding their own biases. Do I suspect that some people really have a penchant for the attractive, elegant, and refined look of dromaeosaurids that has come into vogue? Essentially a grounded peregrine falcon or red-tailed hawk? That such elegant, attractive, and appealing visages have a conscious or subconscious appeal to many of the artists and fans who endorse such a look even going so far as to assert "this is how they looked, period". Wrapped up in a nice little bow because of the RPR hypothesis - which as I have mentioned again and again Fowler stated specifically dromaeosaurids were not as strong graspers as modern accipterids - fueling the typological thinking to dress up a Deinonychus as a grounded red-tailed hawk? And that people who have such a definite and emotional attachment to such a look would be dismissive and threatened by my interpretation asserting a more vulturine influence? Nah, that never could happen snark, snark...

Just to keep in mind I am getting my inspiration from birds too, and not all birds are concerned with looking regal and elegant...

For every grey-crowned crane I can raise you a helmeted hornbill;

helmeted hornbill. Rhinoplax vigil Doug Janson CC3.0
For every great blue heron I give you a marabou stork;

Marabou Stork (Leptoptilos crumeniferus) credit Rusty Clark CC2.0
(end of rant)....

Truth is we do not have a lot to go on in terms of facial appearance of the medium to larger dromaeosaurids that lived in open and/or hot & arid environments. Painting with broad strokes I would lean more towards fully feathered heads for smaller dromies/small game specialists especially in closed temperate environments - essentially Liaoning. But for dromies that were out in the open, fighting and competing over carcasses, going toe to toe with carchs, abelisaurids, and tyrant lizards, in hot and/or arid environs a naked head with fleshy adornments is a defensible position. Many of the more famous dromies such as Velociraptor, Deinonychus, Utahraptor, and Dakotaraptor fall in this category.

credit Charlie Hamilton Jones Getting Cozy With Vultures
Large exposed patches of skin on the head and neck can serve a thermoregulatory function and also social signaling. Blood can be flushed into caruncles, necks flaps, and other skin adornments in colorful threat dominance displays as occurs in condors.

Andean Condor credit Kevin Law CC2.0
Whenever I talk about fleshy skin adornments on theropods - including large lips - there is a consistent critique that people chime in with: "but these areas would be targets for biting by conspecifics and get snipped right off!?!"

Let me offer some rebuttals (takes a deep breath):

1) Losing a chunk or flap of skin is still preferable to losing an eye or getting a bite on the neck or vertebral column which could have fatal results. That being said skin can be amazingly strong, elastic, and (best  of all) it grows back. Hyenas, bears, badgers and yes vultures are often noted for the strong and elastic properties of their skin that allow them to suffer abuse that would seriously lacerate lesser skinned animals. Theropods - and especially combative dromies - had all the reason to not only have such thick and elastic skin but abundant skin derived display structures. Just look at the skull of a male andean condor, there is no tell tale osteological signifier that it looked like the mug above.

2) Which brings me to my next point. We already have compelling and irrefutable osteological evidence of display structures on other theropod skulls (Dilophosaurus, Guanlong, Monolophosaurus etc. etc.). That these animals would grow such features in a highly visible and vulnerable part of the body complete with thin struts of bone - and they were not snipped right off - is all the more compelling reason to suspect a more widespread and outlandish panoply of soft tissue structures throughout theropoda (and many dinosaurs in general) that would not preserve. Especially among those theropods that were regularly coming together socially at large carcasses in feeding events/social gatherings. Dromies certainly count in that regard. In fact we should predict such structures.

3) Which leads right into my next point - prediction met (sort of) !! By now many readers have doubtless heard of the (as yet undescribed) evidence of a large distensible gular neck structure on a Tarbosaurus bataar. If this story pans out we do have evidence of a fleshy display structure on a lineage of the most bitey theropods of all time in the most vulnerable part of the body. So putting a highly visible, likely brightly colored display structure on the neck of the most powerfully biting terrestrial tetrapods of all time still panned out in the Darwinian struggle.

4) Such critics have probably never really been in a fight or done poorly in one... really don't take it as an insult because fighting and violence in humans is not really a good trait to endorse. But looking at what professional fighters and strikers do and the tactics that they use can be useful. One common tactic  used in boxing is to intentionally offer up a shot that puts your opponent in a vulnerable position by feinting a move and then counter-striking.  Let's go through what happens when a "vulnerable" fleshy skin adornment (or large lips) are bitten by another theropod.

I In a dispute one theropod bites the skin flap on the chin of another theropod. Due to the strength and elasticity of this skin it is not simply cleaved right off but instead substantial yanking and pulling would be needed to remove such structures.

II As the theropod that did the biting - let's call it theropod A - pulls and yanks that piece of skin off the bitten theropod - theropod B - and finally cuts clean the skin structure the momentum of the pull off will move theropod A downward and lateral from theropod B.

III At this point it is theropod B - the bitten theropod - that has tactical advantage. Theropod A in the course of yanking off a chunk of skin has put its head and neck inferior to theropod B.

IV Theropod B can now attack theropod A and get a potentially fatal or devastating bite to the back of the neck or head of theropod A. More importantly theropod A can not retaliate when bitten from this position at the back of the neck/skull.

V Theropod B has lost a piece of skin that can potentially grow back. Theropod A has in its miscalculations put itself in a vulnerable position and although it successfully inflicted non-fatal damage by removing a chunk of skin it may potentially lose its life because in doing so it left the back of its head and neck open.

"Bite my lips I dare ya'" credit Tiia Monto CC4.0
Watch brown bears fight. Their big, jangly, fleshy lips are mere inches from one another yet they are not targeted. Because bears are better tactical fighters than most people. Bears know better than to commit to a non-fatal attack that might leave them open in the end.

One final word on theropod facial biting/skirmishes. I suspect the vast majority of bites were not the bone scraping/puncturing potentially fatal traces we see in the fossil record. The overwhelming majority of interactions that went beyond theatrical displays and gesticulations were probably the fast little nips and non-committal bites we see among canids and social feeding birds. Many of these bites would not even break the skin.

Ruppels Vulture bites another, showcases tough, elastic skin. credit. credit Charlie Hamilton Jones. natgeo
I will delve more into display structures in theropods in the future because I think that they are a fascinating topic for exploration. Instead of asking how much or how little these feature were found in theropods - as you can tell I suspect that they were quite widespread - I think we should be asking why are mammalian predators (and I guess you can extend this question to predatory monitor lizards) so impoverished when it comes to display features?

A Long History Of Dromaeosaurid Evolution Lots of Room For Variation

If we accept a middle Jurassic origin for dromies of about 167 mya that gives us more than 100 million years of dromaeosaurid tenure of small and medium sized carnivorous theropod. That is longer than felids or canids have been around. More importantly that is longer than ratites have been around.

I really want to drive home the ratite comparison because dromaeosaurids are increasingly likely secondarily flightless - probably evolving from something like Microraptor that could glide if not fly in a limited capacity. So if we look at ratites it becomes apparent that they have done all sorts of weird things with their feathers once they became permanently grounded. Especially so with their flight feathers. Ostriches no longer have the stiffened vennaceous wing feathers of flighted birds but more open plumaceous ones. Cassowaries have quilled wings. These options are real possibilities for dromaeosaurids but should be analyzed and imbued within a likely evolutionary/ecological framework.

Cassowary. credit Gambier Bolton
In my last post I depicted a Dakotaraptor that veered very far away from other restorations. What I put in that rendering is quilled tail feathers. No need to incur drag when you are that cursorially adaptated. No longer a flighted animal or even one that could glide at that size I posited quills on the tail as a weaponized exaptation useful for whipping around at theropod dinner parties and also for rattling in threat display.  Visual, auditory, and physical threat and intimidation displays should all be on the table when considering dromies. They were likely some of the most gruesomely theatrical animals when gathered in group feeding bouts in the history of terrestrial carnivores.

I also gave Dakotaraptor a striking white feather patch on the front of its chest for bold display and intimidation. Such bold white patches - when contrasted against darker integument - are common in birds of prey and also some mammals such as various species of Asiatic bear.

Ursus thibetanus. credit Guerin Nicolas. CC3.0
I took this notion of feather disuse and even extreme reduction further in a rendering showcasing a Dromaeosaurus feeding scrum on a non-descript chasmosaurine ceratopsid. An azhdarchid and a troodon are looking on waiting for scraps.

feeding scrum by Duane Nash click on image for bigger shot
As you can see I really took the hyena analogy to the extreme even to the spotted scruffy coat. I reduced the wing feathering and eschewed tail feathers completely as this ground based, running, scavenging dromie had little need for them.

I also gave Dromaeosaurus a thick neck mane of coarse feathers for protection during skirmishes.

100 million years of terrestrial evolution from likely flighted ancestors allowed for substantial variation in appearance and function of dromaeosaurids; modern flightless birds show that flight feathers can become plumaceous or quilled; aggressively combative, usurping, and scavenging dromaeosaurids especially in hot and/or arid environs likely featured large areas of the head, neck, and chest bare or with feather reductions; such areas could have sported extreme skin adaptations that offered thermoregulatory, protective, social, and intimidatory benefits; for these dromaeosaurids new world vultures (cathartidae) and old world vultures (accipteridae) might offer more useful analogue behaviorally and physically than raptorial birds of prey (accipteridae); feathers could additionally have been arranged in coarse manes or thick tufts around the neck for protection as well as bold white/dark contrasting areas for intimidation.

One final note and this has to do with anthropomorphism - the ascription of human values, conceits, and emotions onto animals. One charge I have seen leveled at me is that I, to paraphrase, "depict many of my animals intentionally weird, ugly, or unattractive". To which I reply "duh, goal achieved".

I have always been transparent with my inspirations culturally on this blog - informed as I am by ugly music and ugly movies. I think it important that researchers be transparent with their inspirations, not just their scientific ones, to most reveal potential biases. We are all primarily cultural critters and it would be naive to think even the strictest and staunchest scientists are not first and foremost cultural creatures.

So when one looks at vultures gobbling and skirmishing over a carcass or the scruffy, uncouth appearance of hyenas and their cackles and the words "horrific", "disturbing", "ugly", and "revolting" are bandied about is this a cultural reaction or a more intrinsic, base natural one? Let us flip our way of thinking about combative scavengers... do we think about them with these conceits in our mind because of culture, or, because we ourselves are animals and most animals want to move away from the sight of such animals feeding? That is the that the shock, the visual awe, the intimidation we feel at the sight of these feeding events is the same gut level emotional response other animals feel: "I don't want to get near this cancerous looking, tumor faced, loud, shrill, dominating, repellent, and combative animal not because of some cultural tradition but because I too am an animal and I react on a visceral level to this display?"

Coming up a new hypothesis on dromaoesaurid biting technique because it really is all about the teeth...

"A Long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defense of custom". Thomas Paine

Support me on Patreon.
Like antediluvian salad on facebook. Visit my other blog southlandbeaver.blogspot
Watch me on Deviantart @NashD1Subscribe to my youtube channel Duane Nash.

Friday, June 24, 2016

Making Dromaeosaurids Nasty Again Part II - No Shame In the Scavenging Game

Scavenging gets no respect. There is a reason you don't see hyenas and vultures put on coats of arms or have sports teams named after them. Lions and eagles yes, but never vultures and hyenas - ironic that all of these animals do scavenge (and hunt to various degrees). Doubly ironic is that in carcass disputes it is often vultures and hyenas driving the eagles and lions off of carcasses. It is a pet theory of mine that  what makes an animal an exquisite and refined hunter often works against them in carcass disputes. Because the refined hunter depends heavily on preserving the physical armaments that allow it to do its job it is at a disadvantage compared to more generalized opportunistic competitors who can be more reckless in battle. To make the sports analogy it is the difference between the tactical and technical boxer whom excels in the specific and controlled environment of the boxing ring and the unrefined street brawler. The highly skilled and nuanced technical abilities of the boxer will win the day over the street brawler in the ring for sure. But take this tactician out of the ring and into the street against the brawling street fighter - who fights dirty, uses bluff and swagger, and can simply take chances with regards to life and limb that the professional boxer can't - and the outcome swings in favor of the brawler. What makes a good street fighter work well is a different skill set than what a boxer has and what makes a good scavenger work well is a different skill set than what a specialized hunter has.

Cue youtube videos:

Note how the tawny eagle just can't hang with the vulture hordes. A better hunter the eagle definitely is - but a better brawler than the vultures? Sorry the eagle just can't bang with the vultures.

Of course I have to include a clip of my hometown hero the California condor displacing the largest eagle of North America the golden eagle. "Step up to me Mr. Eagle?!? Pwwwfff my ancestors used to go to toe to toe with teratornids over mammoth entrails! Go hunt some rabbits!!"

Don't forget to include mention of the epic dominance of cinerous vultures (sometimes called Eurasian black vulture not to be confused with the New World black vulture) Aegypius monachus which often usurps the golden eagle.

Were dromaeosaurids more the vulture or eagle in carcass disputes? Given that dromaeosaurids did not rely on flight to hunt and may have been afforded wing pummeling; that they were literally armed from head to toe in terms of combative weaponry; that they were good sniffers; that we have evidence very suggestive of scavenging; and the ecological imperative to do so; dromaeosaurids were likely very good facultative scavengers. Yeah, so I lean heavily towards more of a vulture than an eagle in these animals. Both in appearance and demeanor.

Taking the theme that I started with on my last post - an over reliance of the import of the "killing claw" in all endeavors dromaeosaurid and refining the dominant RPR model of a "ground hawk" dromaeosaurid - I am going to expand on that in terms of how and why dromaeosaurids were very good, capable, and successful facultative scavengers. The caveat being, I should just explicitly state, that this does not imply a lack to or unwillingness to hunt. But one more thing about that hypertrophied second digit - the "killing claw". It seems several vultures sports such an enlarged second digit - the magnificent cinerous vulture (Aegipius monachus) and the red-headed vulture (Sarcogyps calvus) pictured below.

red-headed vulture (Sarcogyps calvus) credit Dibyendu Ash CC3.0

cinerous vulture (Aegypius monachus) CC3.0 credit Mistvan

Enlarging the toe on the second digit serves a useful purpose in pinning meat down which allows the beak and head to get leverage in pulling bites off. The "killing claw' in maniraptorans might have been used just as much if not more in leveraging good bites while scavenging/feeding as opposed to outright "killing". Additionally the line of action on the dental serrations suggests that the denticles on the back end of the tooth - the lingual side - were doing most of the cutting work as the animal pulled back on food items. It really is all about the teeth and jaws anyways...

Achillobatar scavenging ankylosaur Talarurus by Duane Nash

Ecological practicality of terrestrial scavenging; optimal size; factultative vs. obligate terrestrial scavenging

First things first. The issue of ground based scavenging. We have all heard the argument "you can't have an obligate ground based scavenger because there simply isn't enough carcasses to sustain such an animal". Sounds reasonable enough and this was one of the trump arguments used to disavow the scavenging T. rex hypothesis. Is there a way to test it?

Some researchers recently did just that in a particularly ingenious and creative manner: Body size as a driver of scavenging in theropod dinosaurs (Kane et. al., 2016). Under various conditions of carcass detectability, carcass size, and competition they performed basically a SIMS version of let different sized theropods find dead stuff and see what body size pans out to be the most efficient in terms of cost/benefit analysis. Basically if you are looking for carcasses to supplement your diet the results are congruent with the assertion that only soaring scavengers can make a total living off of scavenging. Both small theropods and large ones had difficulty earning enough calories from facultative scavenging to make the activity worthwhile. If we think about the issues faced by both very small and very large theropods in terms of garnering benefit from scavenging this makes sense. Small scavengers can't cover as much ground and are easily displaced from carcasses. Large theropods - although they can dominate a carcass - have to move all that weight around and by the time that they detect and reach a carcass much of the available calories might already be consumed by smaller and more numerous scavengers.

What the researchers came up with is very interesting in terms of optimal body size for a land based scavenging theropod. There appears to be a mid-sized sweet spot. Small fry like microraptorines didn't do so well and at the other extreme multi ton giants like tyrannosaurids and carcharodontosaurids did not fair too well as facultative scavengers. Facultative scavenging is most optimal in terrestrial theropods in a size range of between (they get pretty specific) 27 and 1,044 kilograms.

Dromaeosaurids slot into that size range very nicely you should note.

While I have read of several people poo-pooing this paper and its conclusions I personally find a lot of merit (with some caveats of course) in this methodology and the conclusions reached. At the lower end of the size scale I would think that Velociraptor and Dromaeosaurus would still  fair pretty well even though they are lower than 27 kilograms. Jackals and coyotes do pretty well as factulative scavengers and they are a bit smaller than 27 kilograms. Additionally at the higher size range let us keep some perspective. Imagine just >one< 50 ton sauropod died in an ecosystem with several multi-ton theropods and loads of smaller and immature theropods. Chances are the big theropods could locate, dominate, and feast on that sauropod for a while. Their large size and relatively slower metabolism might allow them to scarf down a load of meat that sated them for several weeks or even months. So the big boys might scavenge less frequently but when they do dominate large carcasses that glut of food might form the bulk of their caloric intake for quite a while.

Not to mention this paper completely jives with the conclusions of a similar paper that came out in 2011 that has gone a little overlooked... when two independent studies reach similar conclusions that should perk your interest. The 2011 paper is called Intra-guild competition and its implications for one of the biggest terrestrial predators, Tyrannosaurus rex (Carbone et. al. 2011).

Here is my favorite excerpt from the results:

Physical evidence suggestive of scavenging

Dave Hone has written a bit on Velociraptor consuming and - in his interpretation - likely scavenging azhdarchid pterosaurs  here and here. Make sure to go back and read the commentary it is hardly a close and shut case of scavenging. Hone makes a more compelling case for Velociraptor scavenging a hefty size Protoceratops "fighting dinosaurs", part II. Hone also has some papers on the topics but they are not open access, shucks. The blog posts and commentary get the point across though.

credit Brett Booth
Phil Currie and colleague (1995) also describe another azhdarchid consumed by a velociraptorine theropod but don't conclude it was scavenged.

I don't fully agree that the idea of a velociraptor taking down a 2-3 meter wingspan pterosaurs is nonsensical so for me that is equivocal proof of scavenging. However the scraping of flesh off the jaw of the large Protoceratops is a more compelling argument for scavenging.

Additionally you have the famous Yale Deinonychus and Tenontosaurus quarry that might indicate not only scavenging but aggressive intraspecific killing and cannibalism among Deinonychus. And who knows what surprises await us with the new Utahraptor block James Kirkland and co. are working upon...

Roach and Brinkman (2007) advocate a "diapsid like" foraging strategy in Deinonychus and other theropods as the best and most parsimonious null hypothesis. They eschew the notion of cooperative pack hunting posited to bring down herbivores that are several orders of magnitude larger than the theropods but instead highlight scavenging, combat, and cannibalism as the likely culprits that resulted in the taphonomic signal from the Yale quarry. Chief among these is the presence of articulated tails in the quarry the argument being that the bony and tendonous tails were eschewed in favor of more meaty pieces that were hauled off. I do agree with a lot of what they are selling. They do leave the opening for opportunistic group foraging where a congruence of factors might lead to a "mobbing" type foraging scenario. We see this with sharks gathering escorting ailing whales along and literally eating them alive. Or crocodiles gathering at choice feeding situations or latching onto the same prey animal or loosely "cooperating" to shoal prey together. I would also extend this to the manner in which vultures gather around a carcass and use strength in numbers to harass and intimidate other predators off a carcass.

The blog post Raptors: Do They Live up to the Hype (part 2)? Goes a bit further into the Deinonychus saga if you want to go further...

My purpose here is not too weigh too heavily on whether each of the above scenarios are unequivocally evidence of scavenging but merely highlight that there is a body of evidence that points heavily in the direction of scavenging in dromaeosaurids.

On Hell (Creek) Patrol With Dakotaraptor

Few stories in dinosaur paleontology were as exciting and celebrated as the revelation of an honest to goodness mega-dromaeosaur in Dakotaraptor (DePalma et. al., 2015) that inhabited the latest Cretaceous of North America right alongside good ol' sexy rexy. Met with a flurry of fanfare and fan art I decided to let the dust settle a bit before giving this beast the antediluvian salad treatment.

Any epic beast needs a suitably epic soundtrack to go along with it - Judas Priest's Hell Patrol:

Like wild fire comes roaring
mad whirlwind burning the road

Black thunder white lightning
Speed demons cry the hell patrol

There are a few points from the paper on Dakotaraptor that have not received enough attention in my opinion. Specificities that really speak to the adaptations and ecology of an animal that should garner much attention.

Dakotaraptor Is Cursorial

Interpretations of Dakotaraptor that highlight the ecology of this animal as a cryptic, stalker of closed habitats - the "ghost of the forest" scenario - are missing the story that the bones are telling us. This animal was leggy, it was cursorial, and in life it would have departed strongly from the more low slung and slower Utahraptor or Deinonychus.

credit taphonomy CC4.0

I mean just check out those legs!! Keep in mind that this critter was having to go toe to toe with ridiculously leggy young T.  rex and you can imagine the evolutionary imperative to get speedy. Dakotaraptor appears to have made the necessary concessions needed to increase cursorial ability.

As I discussed in my last post there are certain compromises to be made in terms of raptorial grasping abilities in these animals versus cursorial ability as highlighted by Fowler. To review as grasping ability increases the metatarsals shorten for better leverage and strength but running ability is compromised; conversely as cursorial ability increases grasping strength decreases. Also bear in mind that all dromaeosaurids/maniraptorans were relatively weaker than modern raptors in terms of grasping power of the feet - they were not simply overblown red-tailed hawks.

An Interesting Incongruity

If you followed my articles on Spinosaurus and my argument for underwater punting in that animal you  know that I do have a fondness and attraction for anatomical incongruities; two things combined that seem to make no sense but when analyzed in a different light actually offer a more refined animal. In Dakotaraptor we have such an incongruity.

Digit II is hypertrophied. The "killing claw" in this animal lives up to all the hype. Not only is the claw relatively large, the attachment for the muscle and tendons that drive it - the flexor tubercle - is robust. Whatever way in which this animal was using its digit II it is obvious that it has invested heavily in it.

However the incongruity is seen when we move out to digit III and IV where the claws on those digits are not highly recurved nor is there a significant flexor tubercle present. In fact the flexor tubercle is so reduced in those digits to be pretty much non-existent!!

credit Taphonomy CC4.0 arrows point to flexor tubercle in foot claws Dakotaraptor

I mean just look at the contrast in the flexor tubercle attachment in these two claws. For me this is a compelling argument that the classic raptor prey restraint model posited for these animals is lacking. Dakotaraptor was moving further away from grasping things with its foot claws yet at the same time digit II was still large and strong. What is going on here?

Going back to my earlier bit on the cursorial aspects of this animal and resolving its place in the ecology of the environment in which it lived proves useful I contend. Several inferences are useful in giving better precision as to how this animal likely operated.

Inference 1 Dakotaraptor was highly cursorial.

Inference 2 Dakotaraptor - at least in the adult morph - was fairly limited in arboreal capacity. At best they were probably very clumsy in trees due to large size, long legs, and limited foot strength.

Inference 3 Lesser dromaeosaurids, azhdarchids, and tyrant lizards - especially juvenile and rapidly growing teenage rexes - created an especially quarellsome predatory and scavenger ecology. All of these animals would have been usurping, competing, and fighting over carcasses. Azhdarchids, juveniles rexes, dromaeosaurids, and Dakotaraptor all slot into the ideal size niche to be successful facultative scavengers.

Inference 4 Dakotaraptor could dominate pterosaurs, dromaeosaurids, and smaller rexes. However because it could not dominate larger immature rexes - which were still very cursorial - Dakotaraptor itself needed both speed and maneuverability to evade these animals as it was likely not highly arboreal.

Inference 5 The enlarged and robust ungual and claw in digit II primarily aided in combat - especially in competitive skirmishes over carcasses - and assisted in pinning meat down as the teeth, jaws, and neck pulled bites away from the animal (alive or dead). The denticles on the teeth of Dakotaraptor are most defined on the rear (lingual) side as they are in other dromaeosaurids supporting this notion, The RPR restraint model appears less important in this animal relative to other dromaeosaurids in prey capture. Instead digit II could primarily be used in combative endeavors while wing pummeling and the teeth and jaws did the actual killing.

HellPatrolDakotaraptor by Duane Nash

Dakotaraptor may just be a very specialized and rare component of the Hell Creek hunter/scavenger guild. It was large enough and well armed enough to drive off everything but the larger rexes from a carcass. The cursorial adaptations speak to an animal that could cover a lot of ground to find carcasses, prey, and evade larger competitors if need be. In short we see a lot of compromises that facilitated the existence of a sometimes hunter often times scavenger. It was big, but not so big that scavenging became impractical. It was well armed with a massive and powerful digit II but compromised the raptorial abilities of the other digits in favor of cursorial adaptations. The forelimbs were large, feathered, and powerful - great assets for combat, display, and intimidation. In many ways the large and rare Dakotaraptor was possibly like the lappet faced vulture of Africa. Large and strong enough to dominate most other scavengers at a carcass but would step aside for the larger tyrant lizards just as lappet faced vultures dominate other vultures, marabou storks, and jackals but move aside when hyenas show up.

Wings Suggested as Dominance Display

As in my last post on wing pummeling I will get behind another spotential behavior for dromaeosaurid wings that gets surprisingly scant attention - dominance display.

credit Christine Lamberth blog

Such wings could be spread wide over carcasses in order to appear large and more dominant over competitors. Indeed this is the classic show of dominance modern carcass rendering birds (vultures, raptors, petrels) display at carcass disputes. Wing display for intimidation is so painfully obvious I can't believe that such suggestions don't get more attention. I have heard of it before so I can't claim to be the first to suggest it but I am definitely in favor of it. When we look at what modern carcass disputing theropods do with their wings... you have heard that story before though.

Such a shame that vultures do not get the recognition and respect they deserve for their role in modern competitive ecosystems; that they are spiralling into extinction; that they are not posited as the go to analogy for how extinct theropods looked, behaved, and operated when rendering carcasses - despite the fact that, quite simply, they are the modern theropod that does such things most often. Instead grumble, grumble flipping venomous lizards for crying out loud. Venomous lizards.

When you are watching a scrum of vultures feeding you are witnessing a direct portal into to the feeding activities of dromaeosaurids and other theropods in the Mesozoic's past. The theatrical displays; the spread wings; the fast jerky bites; the constant fight for dominance and hierarchy; and, most importantly, the constant and non-stop flurry of motion, action, and violence. Such scenes would be enacted on a much larger and grander scale in the Mesozoic. A difference of degree but not type. A sight both startling and jaw dropping.

lappet-faced vulture and white backed vulture scavenge elephant carcass. credit Chris Fallows CC2.5

Coming up: restoring dromaeosaurids, ugly vs. pretty, and a new hypothesis on dromaeosaurid biting technique!! 

P.S. I will talk of the weird "tail plume" I depicted on the Dakotaraptor in my next post too so don't even ask about it.


Carbone, C., Turvey, S.T., Bielby, J. (2011) Intraguild competition and its implications for one of the biggest terrestrial predators. Proceeding of Biological Sciences. Sep 7(278) 1718 2682-2690. online here

Currie, P., & Jacobsen, A. (1995). An azhdarchid pterosaur eaten by a velociraptorine theropod Canadian Journal of Earth Sciences, 32 (7), 922-925 DOI: 10.1139/e95-077

DePalma, Robert A.; Burnham, David A.; Martin, Larry D.; Larson, Peter L.; Bakker, Robert T. (2015). "The First Giant Raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation."Paleontological Contributions (14).
Fowler, D., Freedman, E., Scannella, J., & Kambic, R. (2011). The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds PLoS ONE, 6 (12) DOI: 10.1371/journal.pone.0028964
Hone, D., Choiniere, J., Sullivan, C., Xu, X., Pittman, M., & Tan, Q. (2010). New evidence for a trophic relationship between the dinosaurs Velociraptor and Protoceratops Palaeogeography, Palaeoclimatology, Palaeoecology, 291 (3-4), 488-492 DOI: 10.1016/j.palaeo.2010.03.028
Hone, D., Tsuihiji, T., Watabe, M., Tsogtbaatr, K. (2012). Pterosaurs as a food source for small dromaeosaurs Palaeogeography, Palaeoclimatology, Palaeoecology : 10.1016/j.palaeo.2012.02.021
Kane, A., Healy, K., Ruxton, G.D., Jackson, A.L., (2016) Body size as a driver of scavenging in theropod dinosaursAmerican Naturalist June 2016, V.187, No. 6

Roach, B.T., Brinkman, D.L. (2006) A reevalutation of cooperative pack hunting in Deinonychus antirrhopus and other non-avian theropod dinosaurs. Bulletin of the Peabody Museum of Natural History 48(1): 103-138

"A Long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defense of custom". Thomas Paine

Support me on Patreon.
Like antediluvian salad on facebook. Visit my other blog southlandbeaver.blogspot
Watch me on Deviantart @NashD1Subscribe to my youtube channel Duane Nash.

Thursday, June 9, 2016

Making Dromaeosaurids Nasty Again Part I - Wing Pummeling Abuse

"Night Terrors" Sinornithosaurus by Duane Nash

Making dromaeosaurids nasty again... Yes, there is a bit of a straw man argument in there because many might say they never stopped being nasty. But it is my straw man to make, tear apart, refashion, and burn to smithereens as I will... so while reading these posts on dromaeosaurids always keep in mind the tug of war between past and present interpretations scientific, artistic and popular. Don't forget as well these animals had a long tenure as small to medium sized predators so there is a lot of room for variation in terms of behavior, physiology, and appearance.

Something has happened to dromaeosaurids. They have went from jumping on the back of giant ornithopods to jumping on the back of opossums. They no longer look like the scaly, crazed, methed out gang overlords of the Mesozoic bestiary but instead dapper, attractive fashionistas that glided out of some Mesozoic audobon photo shoot. The psycho reptoid wolf-lizard of the Mesozoic is now the camera friendly fashion model of the Mesozoic.

Probably my favorite ol' school Deinonychus image credit William Stout
New school Deinonychus taking on smaller game in RPR model credit Emily Willoughby

A very attractive, dapper Deinonychus by Emily Willoughby. CC4.0

While the ol' school raptor I grew up with is now nothing more than a nostaligic memory ready to join the ranks of swamp bound brontosaurus I am not entirely at ease with all aspects of this new dapper "ground hawk" model for dromaeosaurids. Something just does not sit well with me.

First things first, the claw. Dat claw. Second to ol' sexy rexy and his chiseled and ruggedly masculine good looks the "killing claw" of dromaeosaurids and especially Deinonychus is probably one of the most emblematic and iconic elements of the theropod predatory arsenal. Are we focusing too much on the "killing claw" in terms of prey dispatch but negating other aspects such as the hand claws and teeth?

A brief review of several of the more pertinent works that have brought us to where we are now.

The Slashing Claw Denied...

While the youngins today have grown up knowing that the killing claw of these animals did not cut scythe like slashes through the hides of dinosaurian megaherbivores I do have to admit to feeling a pinge of let down in my inner fanboi when this was first revealed via the study "Dinosaur killer claws or climbing crampons" way back in 2005. Essentially what Manning et. al. did was build a robotic hydraulic Deinonychus antirrhopus claw and lower leg and attempted to drive it through a pig carcass. Instead of the meter long slashes of lore the results were a little underwhelming. The claw did puncture the carcass but as they attempted to drive it through the flesh tissue simply bunched together below the entry preventing a long slash wound.

In comparing the morphology of the claw they found it most lined up with the claws of climbing animals. Manning et. al. did not totally eschew the notion of dromaosaurids leaping onto the sides of megaherbivores but offered an alternative; the killing claw was now a crampon which allowed the predators to jump onto the side of prey and deliver slashing bites with the jaws.

Jumping on the Flanks of Giant Herbivores Denied...

Seems pretty legit right?

Well the next paper seemingly expunges the use of the claw in climbing onto the back of megarherbivores. Enter the Raptor Prey Restraint model (RPR) which probably needs little introduction to most readers here. Fowler et. al. reject the notion of dromaeosaurids latching onto the flanks of large herbivores and slashing at prey with foot claws or teeth. Instead prey subequal to the size of the dromaeosaur is pinned down beneath the weight of the predator; stability flaps of the "wings" and movement of the beam like tail help maintain an upright position; and prey is essentially eaten alive if it is not killed outright by the feet.

And you know... I like this a lot. It makes sense - there is a good analogy with modern accipitridae and it has a nice little thematic thing going on with the flight exaptation given that dromaosaurids are likely secondarily flightless. The authors also make a very striking contrast between dromaeosaurids and troodontids that suggests a degree of partitioning between the two groups. Dromaeosaurids had shorter but more powerful metatarsals suggesting a larger prey size seized by the feet than troodontids which compromised strength for cursorial ability and a quicker grip on smaller prey.

So ground hawk Deinonychus... what is not to love?

There are some caveats to this model that the authors address that I think warrant repeating:

So, despite the arguments in favor the RPR model for dromaeosaurids and the inherent attractiveness of the model it appears that dromaeosaurids were not >as good at it< as their modern avian counterparts. I am not saying RPR is not a thing and, again, this is from their own paper but it appears that a 50 kg Deinonychus is not equal to a scaled up 50 kg red-tailed hawk in terms of relative grasping power of the feet. Furthermore if you look at the vice like grip that modern raptors can enact in which digit I is rotated completely opposite the other three digits it appears that Deinonychus and other dromaesaurids do not fully rotate the digit opposite the other three for a truly powerful vice like grip.

credit eaglesohio
Again, not trying to imply that RPR is not a thing for dromaeosaurids or that they did not pin and even kill prey with their feet but let us be clear with what the science shows as of now. In dromaeosaurids the RPR model is a relatively less powerful and less efficient version than modern raptors essentially due to the anatomical concessions of retaining some cursorial ability. But I am sure it was still unpleasant...

Actually what dromaeosaur foot graspers remind me of is cats claws and paws (gasp!! mammals). No really... anyone who has had a cat "knead" on them (i.e. breadmaking) knows what I am talking about. As the cat's claws clench shut in a semi-opposable fashion the claws actually pin stuff against the lower arm. In dromaesaurids grasping things would be pinned against the bottom of the metatarsus. This is still a pretty good grip and with both legs working together likely very efficient.

Dino Kitty
The Role of the...

I am obviously not the first to ponder this and it is a perplexing issue in many, if not most, predatory theropods - but what were the clawed wing/arms of dromaeosaurids good for anyway? Fowler et. al. posit them as dynamic stabilizers that combined with the fully feathered tails (like Archaeopteryx not Caudipteryx plumes) allowed these predators to maintain vertical superiority via flapping over prey caught in the foot claws. I like this a lot. So please don't misquote me when I argue that there is something to augment this method not completely replace it.

Those big hand claws seem like such a waste if all they did with their arms is use them in stability flapping.

Issues have been raised as far as the practicality in using the hand claws to grasp small prey dexterously or even bring the hands together to grasp small prey with precision. I honestly don't know what the current thinking on this issue is - or if there is any consensus at all? I would love to hear thoughts and input in the comments section... From what I gather on my cursory research things seem a little equivocal. The wikipedia page on Deinonychus mentions papers that support grasping and others that bring forth some practical questions. Some observations that cause me to question fine tune grasping of small prey items include the potential issue of the "wings" getting in the way of each other when brought together. Also and this is my general observation of patterns in clawed grasping animals: it seems reasonable that in order to achieve a powerful and concise grip that the digits and claws work better aligned in a similar plane. Essentially when you look at the grasping claws of a felid, modern avian raptor, or hell... even our own hands what you see is the digits not varying tremendously in terms of length and that they line up together relatively closely when clenched.

This was simply not the case in maniraptorans with extremely divergent digit length. Such spindly, long claws just seem a little less than ideal for enacting a powerful and concise grip on something small that needs precision. Gripping a tree trunk or "bear hugging" an animal that is fairly large yes... but dextrous grabbing and manipulation of small stuff, I don't buy it. Especially with all those feathers in the way. Could hands like the ones below deftly grab and pick up say a scurrying lizard or mammal? 

credit John Conway. Deinoncyhus (L) Archaeopteryx (R) CC3.0
The digit lengths are just different from the pattern we see in other grasping predators even other theropods. For example in Allosaurus fragilis:

Allosaurus hand. credit Domser CC3.0

Another point is that if a dromaeosaurid wanted to reach out and grab a small prey item doing so with the head and mobile neck or even the feet seems more ideal. The arms - like all theropod arms - had limited mobility in the forward plane. Several of the problems in forelimb usage are summarized in a paper by Phil Senter comparing the forelimbs of Bambiraptor and Deinonychus:

For these and other reasons I find  "fine tune grasping of prey" hypothesis more than wanting. Enough so that other hypotheses warrant exploration.

The hypothesis I will offer - not sure if this idea has been explored yet anywhere to tell you the truth - is going to highlight exaptation of the flight stroke and musculature of the maniraptoran arm to a high degree. This is consistent with the strong hypothesis put forth by Gregory S. Paul that dromaeosaurids are secondarily flightless.

The clawed wing arms of dromaeosaurids could potentially act as clawed battering tools that would further bludgeon, wound, and traumatize prey and/or competitors especially that have been pinned by the feet.

Why not? The arms were strong, long, and heavily clawed after all. More so modern birds just love to bludgeon and smack other things around with their wings. Made famous in a series of posts at Tet Zoo(here 1, part 2part 3wrestling birds) by Darren Naish, some wings even have weaponized claws, clubs, and spurs. Dromaeosaurids - likely being secondarily flightless - already had the exaptation to use their wings as bludgeoning tools. All the musculature was already set up for it.

Two Deinonychus have a disagreement. Provided by Robin Liesens (Dontknowwhattodraw94)

As I mentioned earlier the study by Fowler argued quite well that dromaeosaurids were not >as good< as modern raptors in terms of prey dispatch via the foot claws. Other tools might be needed for prey dispatch... Why not use those nice hand claws powered by the incipient flight stroke to further gouge, pummel, and weaken prey that is being grasped by the footclaws and jaws? Not saying stability flapping did not happen just that stability flapping used in conjunction with with wing pummeling might have some merit. Furthermore the need to maintain vertical position over prey might be just a tad overstated - don't forget the fighting dinosaurs!! After all dromaeosaurids had a little bit more liberty in terms of getting down and dirty on the mat as opposed to accipterids which always have to be mindful of getting grounded with a serious wing injury.

CC 2.0 credit Yuya Tamai. Protoceratops & Velociraptor
And modern birds do love to fight and 'rastle!!

Did you check out that eye gouge at about 1:03? Note how right above the eye is nice a ridge of brightly colored, caruncled tissue... remind you of a suggestion I made before?

Or the above video which actually doesn't feature a stork eagle fight but loads of domestic breeds battling one another (uuurgh there Nash goes with domestics again). Loads of fleshy caruncled faces, face biting, wing pummeling, talon thrusting. In short very awesomebro!! but not necessarily without merit just because it is awesomebro!! You see the pattern - lunges and strikes are made with the head and/or feet. When brought into the line of fire of the wings, pummeling commences.

Tsaagan dispatching Velociraptor. work in progress Duane Nash

This methodology of prey capture/combat is essentially a bit of an inverse of a common tactic used by felids. Anyone who has a pet cat  (or who has a cat that has them?) should be familiar with it. If not simply stroke the vulnerable belly of a said felid and the forelimbs and/or jaw will lock into your arm and the back legs commence clawed kicks. In dromaeosaurids it would be the hindlimbs and jaws locking prey into place and the forelimbs delivering blows and trauma via wing pummeling.

Deinonychus wing pummeling Zephyrosaurus. credit Robin Liesens (Dontknowwhattodraw94)

In addition to the analogy to modern bird wing pummeling the analysis of theropod stress fractures and forelimb avulsions (Rothschild et. al., 2001) came up with some interesting results with regards to Deinonychus limb use: 43 hand bones and 52 foot bones were examined for signs of stress fracture - none were found. However the second phalanx in the second toe (the killing claw) has a healed fracture (YPM 5205). Why is this important? Well it suggests that the hand claws are not hooking into things and holding them tightly such as appears to be the case with Allosaurus which shows multiple manual pathologies - but the healed killing claw suggests that digit II is hooking into and holding struggling prey/combatants to a higher degree. On the other hand it is worth asking why wing pummeling would not create stress fractures? Perhaps with the force being distributed across the whole surface of the wing (including the feathers) stress fractures would not be such a problem? Are stress fractures a problem in modern birds that wing pummel? Could be an avenue of exploration...

Really I am quite surprised that wing pummeling in dromaeosaurids (and other winged dinos/maniraptorans) has not been proposed before... I mean has it? I dunno, can't find any mention and it seems like a pretty logical inference from what I have gathered.

Two potential criticisms I want to address:

"Yes but modern birds use this wing pummeling in antagonistic disputes not predatorial. Birds of prey do not batter their prey with their wings."

True. Remember Fowler quite convincingly argued that dromaeosaurids were not  as relatively >strong< in grasping as accipterids. Does this imply that they were small game specialists? I think not. My contention is bolstered by the "fighting dinosaur" specimen. You will hear some researchers try and explain this situation away as a "rare" or "aberrant" exception to the "baby killer specialist" or "small prey only" model. With all due respect I think that they are mistaken. Not that loads of baby dinosaurs were not munched on, merely that dromaeosaurids and most theropods were not "specialized" for that task.

Given that dromaeosaurid foot grasping was meh compared to modern birds of prey but they were still getting into the thick of things with some pretty rugged combat other lines of attack should be invoked. Those big hand claws seem awfully put to waste in mere stability flapping. Especially when attacking strong retaliatory prey like protoceratopsids.

"Why don't birds of prey pummel prey with their wings?" As I alluded to earlier accipterids differ from dromaeosaurids in that they are dependent on flight. Wing pummeling for them may be selected against as a predatory strategy because they risk an injury, not to mention their feet do the job just fine.

"What about the claws getting stuck in the flesh and skin of the prey during pummeling. Could that be a problem?"

I don't think so. If the downstroke can enmesh the claw in the animal then the upstroke can pull them back out. If claws getting stuck in stuff was so much a problem I guess that implies these animals could not use their claws to climb and clamber in trees as well, because their claws would get stuck in wood, amirite?

Given that; dromaeosaurids are likely secondarily flightless; that their digit morphology is aberrant from other predatory "graspers"; that wings may have got in the way of grasping, especially of objects on the ground; that the fingers remain spread during flexion; that one handed clutching of objects to the chest is just weird; that the elbow can not be fully extended and forelimb mobility is limited;  that extant aves often use their wings - sometimes coupled with knobs, spines, and claws - to pummel other animals; for these reasons I posit the hypothesis that clawed wing pummeling is a promising tactic used in dromaeosaurid predatory, combative, and defensive endeavors.

At the moment I see no reason that the idea of wing pummeling can not be extended to other winged dinosaurs and maniraptorans. Hello wing pummeling GallimimusGigantoraptor, Therizinosaurus, and Deinocheirus!!

Next up: biting, scavenging, scrumming, and bone cracking dromaeosaurids.


Fowler DW, Freedman EA, Scannella JB, Kambic RE (2011) The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds. PLoS ONE 6(12): e28964. doi:10.1371/journal.pone.0028964

Manning, PL, Payne, D, Pennicott, J, Barrett, PM, Ennos, RA (2006) Dinosaur killer claws or climbing crampons. Biology Letters (2006) 2 110-112 pdf

Rothschild, B. Tanke, D, Ford, TL (2001) Theropod stress fractures and tendon avulsions as a clue to activity. Mesozoic Vertebrate Life. editor Tanke, D & Carptenter, K. Indiana University Press pp331-336

Senter, Phil (2006) Comparison of forelimb function between Deinonychus and Bambiraptor (Theropoda: Dromaeosauridae). JVP Volume 26 Issue 4 2006

"A Long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defense of custom". Thomas Paine

"It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deed; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place will never be with those cold and timid souls who neither know victory nor defeat." Theodore Roosevelt

Support me on Patreon.
Like antediluvian salad on facebook. Visit my other blog southlandbeaver.blogspot
Watch me on Deviantart @NashD1Subscribe to my youtube channel Duane Nash.

As I have seen an uptick in traffic and subsequent comments that lower the standard of conversation on this blog I will be moderating the comments section from here on out. I don't have a comment policy other than it is my blog and I will do whatever the hell I want to with it and ban whoever and whatever comments I want. Disagree with my ideas - fine, disagree with me so strongly that you launch smear campaigns and rants against me... fine... go make something original on your own. You will still be banned here.  As several recent commentators now are - banned for life. It should not be too hard to find out who those are from recent posts as I will leave their comments up as fair warning to others.

There is a big ol' internet out there and I don't need you.

Over all though I am happy with the input, differences of opinion, and general intelligence of the commentators. You guys are my "peer review" as much as I can muster at least and have helped me change and refine my own thoughts and perspectives numerous times. Keep it up.

Sorry if you thought that theropod lip post was happening now, a little bait and switch hahaha... some other stuff beforehand that is very interesting to build suspense...  but I am still coming for ya' lizard lipped theropods.

Related Posts Plugin for WordPress, Blogger...