tag:blogger.com,1999:blog-8161161431451849208.post4088935192341868485..comments2024-03-28T02:45:03.204-07:00Comments on Antediluvian Salad: Night Stalker Rex Part I: Sue Is Built Like A BrickhouseDuane Nashhttp://www.blogger.com/profile/14467779935085970909noreply@blogger.comBlogger31125tag:blogger.com,1999:blog-8161161431451849208.post-19471283875920529182017-07-19T09:08:39.523-07:002017-07-19T09:08:39.523-07:00@MrCrow Thanks, and people have brought that point...@MrCrow Thanks, and people have brought that point up to me before.<br /><br />A couple of things:<br /><br />1)The review by Carpenter did not focus extensively on night vision and it is barely a paragraph in which it mentioned.<br /><br />2) We don't have T. rex sclerotic rings they are inferred from relatives. Carpenter inferred eyeball/width ratios based on just one sample a Caribbean flamingo. <br /><br />3) Carpenter gets his reasoning from a paper on Ichthyosaurs and looks at just one avenue to determine night vision capability. http://mygeologypage.ucdavis.edu/motani/pdf/motanietal1999.pdf<br /><br />4) Carpenter did not mention the possibility of abundant light sensitive rods, tapetum lucidum, and photoreceptor protiens. <br /><br />5) T. rex only had to have night vision good enough to hone in on prey after its sense of hearing and smell did the real leg work in my estimation (more on this aspect in a future post). Contrast this with ichthyosaurs that relied exclusively on night vision and owls which use hearing and night vision.<br /><br />Given the lack of hard data on eyeball size, unreliable comparison to just one bird (Caribbean flamingo) and omission of mention of other light gathering techniques I would hardly count this rather cursory treatment by Carpenter (just one small paragraph in basically a review paper) as a damning knock on low light vision capability. Probably not as good as other low light visual specialists (owls, ichthyosaurs) animals, but it may not have needed to be as hearing and smell got it to within striking distance of its slumbering quarry in my view.<br /><br />Again a central tenet of my still evolving nightstalker hypothesis is that T. rex is locating slumbering dinosaurs. Often times these will be the young of larger species or more moderate sized ornithopods/ornithomimids. These animals will sleep not in the open but hidden, therefore T.rex is not going to find them by scanning the landscape. Ol' rexy is going to sniff them out and ultimately hear the low frequency sounds all animal make, even when sleeping (hint, hint). Eyesight just needs to be OK in the dark, its not actually the dominant sense in my view. Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-82847610672176694222017-07-19T04:40:38.173-07:002017-07-19T04:40:38.173-07:00@Duane Nash
According to this (https://www.researc...@Duane Nash<br />According to this (https://www.researchgate.net/profile/Kenneth_Carpenter3/publication/289279026_A_closer_look_at_the_hypothesis_of_scavenging_versus_predation_by_Tyrannosaurus_rex/links/58c6dd1f92851c653192b206/A-closer-look-at-the-hypothesis-of-scavenging-versus-predation-by-Tyrannosaurus-rex.pdf), Tyrannosaurus may have had poor vision in low light conditions.MrCrownoreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-37848965588942154082016-11-12T10:35:39.619-08:002016-11-12T10:35:39.619-08:00Hi ted. I tend to avoid asserting any concrete sug...Hi ted. I tend to avoid asserting any concrete suggestions on weight. There are many variables that make even the most rigorous assessments of weight prone to less certainty than we might be comfortable with. Even coming to good weights in living animals is fraught with difficulty. For instance what about skin thickness? The hide of a hippo can weight over a ton... What would this imply for the weight of spinosaurus? If it, as I have argued, had a similar skin thickness - with much more surface area the skin of spinosaurus alone may have weighed 2-3 tons alone possibly!! My final answer for something of a Sue sized rex is it most likely weighed substantially more than a bull African elephant. That is my broad side of the barn best guess answer. In other words - fucking heavy.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-56728371350469988562016-11-04T10:09:26.897-07:002016-11-04T10:09:26.897-07:00How much would Sue have massed in your opinion? Mo...How much would Sue have massed in your opinion? More than any other recorded theropod?tedhttps://www.blogger.com/profile/10853335652206061926noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-10120303121071167812016-10-20T13:30:08.694-07:002016-10-20T13:30:08.694-07:00But to get into a proper position of control the f...But to get into a proper position of control the forelimbs are needed. A bite is only as strong as its ability to reach the targeted area. Not always neccesary but most definitely part of hunting as otherwise there is a massive hole in the defense and control ability of the animal. The head,arms,and legs combine at least partially for the kill and consumption right? An example being that without the use of arms a T.Rex killing an Ankylosaur would be extremely hard to do. Even while asleep it's dangerous as there's a chance of deadly collision.Anonymoushttps://www.blogger.com/profile/11307953614040034920noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-52117373429224967212016-10-18T10:28:36.988-07:002016-10-18T10:28:36.988-07:00I don't really understand the dilemma. T rex -...I don't really understand the dilemma. T rex - and really all other theropods - have a head that is ahead of the reach of the forelimbs, Whatever the forelimbs were doing it was after the prey had been engaged with by the head.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-9838241909077464772016-10-17T12:52:42.339-07:002016-10-17T12:52:42.339-07:00I do have one question though.Would the morph trul...I do have one question though.Would the morph truly be that big? The estimates you showed seemed to make the arms rather inefficient. The discovery of the amount of muscle on the arms of the Rex, seems to be in place for helping it control itself/and or its prey into an angle it can get that bite in. At that size it looks to be rather tough though I suppose using the weight it could still get a proper angle one the prey item. Do you believe in the use of the arms for predation? I have talked to some paleontologist, one admitting that he cannot take back his position as he is entrenched in the arms being uselss.Anonymoushttps://www.blogger.com/profile/11307953614040034920noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-89719548401622092042016-10-06T06:19:02.777-07:002016-10-06T06:19:02.777-07:00Just an update after asking around, it turns out t...Just an update after asking around, it turns out that there are "reports" of the more robust morph being found in the lower Maastrichitian and gracile morphs being found farther up. There are no actual papers on this so take this with a grain of salt, though a famous and (usually) well made* Japanese blog on Dinosaur skeletals talks of this. Here's the blog post from Saurian talking it about it as well with the help of Scott Hartman and Get Away Trike (the info's under the dection called Reference Specimen), so it is even more trust worthy:<br />http://saurian.maxmediacorp.com/?p=553<br />Though don't get it wrong, even the more gracile morphs were incredibly bulky. Basing it off of Stan, the animal itself is more "scrawny" than the average Rex simply because of individual variation. Also keep in mind that it was a young adult so it still has some growing to do. So sexual dimorphism isn't likely.<br />Iris-Katyayanihttps://www.blogger.com/profile/06188961246186305190noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-54541048746896480972016-10-06T05:57:55.088-07:002016-10-06T05:57:55.088-07:00Just a note about the robust morphs of Tyrannosaur...Just a note about the robust morphs of Tyrannosaurus, I remember the Saurian devs talking about how the gracile and robust morphs are actually seperated over time. So one is found in the lower Maastrichitian and eventually evolves into the other morph over the course of the mid Maastrichitian and onwards. Don't take my word for that though. I don't have a scource to link right now and honestly I lean more towards sexual dimorphism myself seeing as how there aren't any full fledged papers on the matter. Just people alluding to it amongst the deeper parts of the paleo community. And I've learned over the years to not trust random conjceture simply because others have said so online. The whole commotion about the "Spike-backed" Dimetrodon is the best example since people hopped onto that bandwagon simply because one or two people started it. The whole unpublished remains of that "piscivorous" Psittacosaurus sp. is another example that I still hear about from time to time.Iris-Katyayanihttps://www.blogger.com/profile/06188961246186305190noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-40303918879622485512016-10-05T14:53:11.711-07:002016-10-05T14:53:11.711-07:00Thanks Alex. Indeed the comparison between T. rex ...Thanks Alex. Indeed the comparison between T. rex and the stealth behavior of elephants is something I will delve deeply into for the next post. Large animals can be cryptic not so much by hiding behind or blending into the environment but by reason of their size just looking like a natural feature of the environment. <br /><br />I get your point about being careful on drawing too much from mounted skeletons. In the case of Sue though since "she" is the most complete large rex I see less reason to question her general build than other mounted specimens. I do suspect that the "gracile" vs "robust" split in rex is a sexual characteristic - something I will build upon in the future.<br /><br />Maybe I need to restate my idea - and why I concentrated on Sue - more succinctly in the next post: that in the ontogenetic trajectory of rex we would see the complete gamut of predatory tactics that other smaller tyrannosaurids utilized. From small game coelurosaur hunter/scavengers, to teenage pursuit tactics, to subadult mixed bag ambush/chase and finally at the "Sue" level a complete mastery of stealth technique refined to the point that she may have specialized in not only short ambush tactics but actually detecting, infiltrating, and abducting sleeping dinosaurs. That is why emphasized Sue so much as I see in her a culmination of size, experience, super senses, and limited agility that necessitated the specialized tactic of catching not only dinosaurs under the cloak of dark - but while they were actually asleep. Of course will build on this in future.<br /><br />I have pondered the long distance pursuit tactic but find it lacking. Again, why pack on so much girth if you want to run for long distances? Furthermore the ginormous jaw muscles speaks to animal that needs to get one good shot in, not something that it harrying and nipping at fleeing dinosaurs over distance. And finally the survival of hadrosaurids after failed predatory attacks is in line with relatively slow ambush predator that - if it doesn't get the first strike in properly - probably loses its quarry.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-25009126280427011252016-10-05T13:58:35.152-07:002016-10-05T13:58:35.152-07:00Very interesting ideas! It reminds me of Phil Tipp...Very interesting ideas! It reminds me of Phil Tippet's "Prehistoric Beast." I'm largely in agreement with you here: we've long attached this Hollywood vision of the Mesozoic to our speculated behaviors for these animals. A stealthy tyrant is not exactly something we're used to thinking about, but even modern day multi-ton animals can be stealthy - I recall a survivor's account from a program concerning elephant attacks, where a villager in India was attacked from behind by an elephant he didn't even know was there. Imagining a much more svelte predator at that size doing the same is not hard.<br /><br />My only concern here is that some of your observations are dependent upon the quality of the mounted skeleton - this is not always consistent across museums and companies that work with fossils. There's probably a reason the Sue mount looks ridiculously bulky, whereas other displayed specimens are not so chunky. Peck's Rex and the Trix specimen are nearly as large, and the latter is also of the robust morph. Looking at their skeletons, you have what is most certainly a large, robust animal, but not one that is nearly as square (or brick-house-ish).<br /><br />Do you think that the one-way breathing system Tyrannosaurus had might have made it a more efficient pursuit predator? Obviously, you aren't attuned to the idea of Rex being a pursuit predator, but it might not have had to run faster, just longer. Food for thought!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-22875362696965429042016-10-03T17:59:09.673-07:002016-10-03T17:59:09.673-07:00I didn't mention them because they seemed like...I didn't mention them because they seemed like the obvious and more recent choices, but no doubt just as important.Anonymoushttps://www.blogger.com/profile/15444274404962614808noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-80986480485674669172016-10-03T16:37:26.032-07:002016-10-03T16:37:26.032-07:00@Jonathan Atkinson Don't forget Nanuqsaurus an...@Jonathan Atkinson Don't forget Nanuqsaurus and Australovenator!Iris-Katyayanihttps://www.blogger.com/profile/06188961246186305190noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-11404800373786871152016-10-03T13:58:45.421-07:002016-10-03T13:58:45.421-07:00Although I totally see how trex would be a good ex...Although I totally see how trex would be a good example of nocturnal large theropods I was honestly thinking you would cover cryolophosaurus what with being in 5 months of mostly darkness. Another time maybe (poor cryolophosaurus).Anonymoushttps://www.blogger.com/profile/15444274404962614808noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-86318767652592040642016-10-02T00:54:22.079-07:002016-10-02T00:54:22.079-07:00Good point about Allosaurus being relatively barre...Good point about Allosaurus being relatively barrel chested, I now recall that it has been noted for its relative girth. But if all you have to do is run down sauropodlets and scavenge giant carcasses not much need for agility too.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-3484004876312772592016-10-01T15:54:17.819-07:002016-10-01T15:54:17.819-07:00Great post Duanae, and I had no clue how effecient...Great post Duanae, and I had no clue how effecient black bears were at hunting. Most people just take them as some kind of "Pooh Bear" that just eats berries all day long. And nocturnal hunting Orcas make perfect sense, and it's a shame that we are only now just devling into their nocturnal habits.<br /><br />And a note about barrel chested Theropods, Tyrannosaurus definitely wasn't the only one for the title of "Brick House with Teeth". I went to the downtown library here in Cincinnati, and because our museum is under renovation a mounted Polar Bear and a sub-adult Allosaurus were on display in the library temporarily. When I looked at this medium sized Theropod at no more than 25 or so feet long, I realized that it too is rather barrel chested. You can clearly see that the body itself encompasses the front viewing,and it blocks the front viewing of the thighs and tail by a good 5 inches or so. 5 inches isn't too much for a 25 ft. animal, but it would be even wider in the real animal when it's covered in fat, muscle, feathers, etc. I have a feeling that most medium to large sized Theropods were barrel chested to a certain degree, in must have been like modern Felids and Ursids in that they too must have somehow used their own sheer weight and girth to subdue prey.Iris-Katyayanihttps://www.blogger.com/profile/06188961246186305190noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-71812321600781792412016-09-30T13:57:56.128-07:002016-09-30T13:57:56.128-07:00Thanks for comment Stevie. With regards to vision ...Thanks for comment Stevie. With regards to vision due to deficiency of vitamin A in herbivore diets predators will always have an advantage over herbivorous prey at night, see in my post where I went into this. If anything nocturnal activity should be our bias our null hypothesis as goes tetrapod predators.<br /><br />Future posts will elaborate and yes smell and vision are key but it is really the feet, hearing, and delayed adolescence that tie it all together.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-15737758238203897972016-09-29T15:22:51.623-07:002016-09-29T15:22:51.623-07:00While I don't doubt for a second the size and ...While I don't doubt for a second the size and bulkiness of adult morph rex's nor their highly attuned senses of particularly vision and smell, I can't help but wonder if their likely prey items would not be nocturnally active themselves. <br />How much do we really know about the active hours of operation for the prey items? If we were to go back to the Lion comparison, or even the whales, do their prey items keep one eye open after dark simply because there is a stalker in the night? Certainly the dimness provides an advantage for night sensory adapted predators regardless of whether or not the prey are awake at night, but being alert during the dark with senses of smell and hearing might help them from becoming a midnight snack.<br />Looking forward to the next chapter.Anonymoushttps://www.blogger.com/profile/09630838114257894524noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-60631561118149229572016-09-27T14:03:17.694-07:002016-09-27T14:03:17.694-07:00With regards to prey size:
Looking at predators t...With regards to prey size:<br /><br />Looking at predators that engage prey significantly bigger than themselves (many by night-see:Savuti lions), most of them are focused more on maneurability than speed.<br /><br />IIRC herbivorous dinosaurs were focused on being able to block an attack from all directions, either by turning quickly or by kicking in all directions. To deal with these defences, a predator would have to be able to dodge quickly and pivot around to get past counters.<br /><br />Comparing the foot anatomy of carnosaurs or dromaeosaurs to tyrannosaurs, their feet and ankles are more flexible, lacking an arctometatarsus. This costs a bit of speed but increases overall agility, because the foot is able to flex as the animal is turning.<br /><br />With tyrannosaurs the arctometatarsus binds the ankle joints and the toes tightly. This provides rigid structural support, but at the cost of flexibility.<br /><br />Combine that with a T. Rex's heavy build and you end up with an animal that will get kicked to death when it engages an animal several times its size, because it would be unable to dodge the kicks. BKhttps://www.blogger.com/profile/03759189747932749283noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-26651114512379564802016-09-26T17:11:42.018-07:002016-09-26T17:11:42.018-07:00Sue-mongousSue-mongousmrplcolehttps://www.youtube.com/channel/UC8jzSxKrLJyWJVvI6wDFoJwnoreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-458778746431607382016-09-26T13:17:34.258-07:002016-09-26T13:17:34.258-07:00Thanks Ryan. "Nocturnal Predatory Defensive L...Thanks Ryan. "Nocturnal Predatory Defensive Linemen" - LOVE THIS!!<br />Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-9079233773419182922016-09-26T12:15:48.821-07:002016-09-26T12:15:48.821-07:00I've always appreciated your blog diving into ...I've always appreciated your blog diving into the "non-mainstream" area of Dinosaurs and prehistory, but it's cool to finally see it touched on. Can't wait to see T. Rex as "Nocturnal Predatory Defensive Linemen" explored further.Anonymoushttps://www.blogger.com/profile/00077775903586562286noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-81647434026083978032016-09-26T11:35:14.551-07:002016-09-26T11:35:14.551-07:00@Trilobite Cannibal Yes, yes it does. New pic comi...@Trilobite Cannibal Yes, yes it does. New pic coming - less facial features prominent, just a general "thickening" of facial skin, upper shoulders & neck. Harkens a bit towards other contemporary depictions but with some weird new stuff. Next post.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-78922160083822827712016-09-26T01:58:22.168-07:002016-09-26T01:58:22.168-07:00With these new thoughts on rex does your vision of...With these new thoughts on rex does your vision of the creature change? Perhaps a sinister solid black on the caruncles akin too a black vulture?Anonymoushttps://www.blogger.com/profile/16487518223946522978noreply@blogger.comtag:blogger.com,1999:blog-8161161431451849208.post-57525089237818039582016-09-25T23:02:26.845-07:002016-09-25T23:02:26.845-07:00@babehunter yes bears use their size and strength ...@babehunter yes bears use their size and strength to grapple and subdue prey, However bears are mainly omnivorous and are not even as barrel chested as rex - rex was an obligate hunter and still had an unparalleled physique for a terrestrial predator, This is the enigma I am exploring.Duane Nashhttps://www.blogger.com/profile/14467779935085970909noreply@blogger.com