Comments on: A New Giant Tyrant, Zhuchengtyrannus

By: Tim Donovan

Tim Donovan — Sat, 09 Apr 2011 12:47:01 +0000

Sure there may have been some overlap between Albertosaurus and Tyrannosaurus but apparently not in the same environment. Upper Horseshoe canyon Albertosaurus specimens approach middle Maastrichtian age, about the same time Tyrannosaurus was evolving in SW environments. I suspect Tyrannosaurus ultimately spread into all environments and blew away the competition.

By: Brian Switek

Brian Switek — Fri, 08 Apr 2011 14:14:19 +0000

Gray: There may have been some overlap between Albertosaurus and Tyrannosaurus, but, as far as we currently know, Tyrannosaurus was the only tyrannosaurid in the majority of the ecosystems in which it occurred during the time it existed. I am not counting Nanotyrannus because no solid evidence has yet been found confirming that this second ‘pygmy tyrant’ actually existed. Specimens referred to Nanotyrannus are most likely juvenile Tyrannosaurus.

By: Gray Stanback

Gray Stanback — Thu, 07 Apr 2011 21:40:21 +0000

Was there ANY time overlap between Tyrannosaurus and other North American tyrannosaurids (Nanotyrannus does not count)?

By: The Tragedy of Tinker | A Central Coast Paleontologist

The Tragedy of Tinker | A Central Coast Paleontologist — Thu, 07 Apr 2011 20:26:00 +0000

[...] post was inspired by my little debate with Brian Switek over at Dinosaur Tracking spawned by my stupid little observation. First off in [...]

By: Doug

Doug — Sun, 03 Apr 2011 17:58:25 +0000

the hiccup i was seeing was with the “5 pounds a day” figure i kept encountering. there’s a specimen called Bucky who’s around the same size as Thomas but i have been unable to find age and weight figure for the specimen. Unfortunately Tinker hasn’t been treated well (hence lack of info on specs) and all i have been able to find for the juvenile in LA’s growth series is that it’s 20 feet long (which is the size of Jane). I have emailed a couple paleontologists about this (have yet to here back). If anything, it may just T. rex grew even faster than previously thought.But i’m probably wrong, as always.

By: Brian Switek

Brian Switek — Sat, 02 Apr 2011 20:39:45 +0000

Doug: I don’t see the same ‘hiccup’ you refer to. Tyrannosaurus rex grew extremely fast, even compared to other tyrannosaurs. See Horner and Padian 2004 (http://rspb.royalsocietypublishing.org/content/271/1551/1875.short) and Erickson et al. 2004 (http://www.nature.com/nature/journal/v430/n7001/abs/nature02699.html), for example.

Additionally, Tyrannosaurus rex individuals would have varied in size at different life stages, so we would need more than two subadult individuals to determine if one or the other really fell outside the expected growth pattern.

By: Doug

Doug — Fri, 01 Apr 2011 17:39:38 +0000

Yeah, now that i think back, it was a pretty good year for tyrannosaurs.

I think the niche partitioning between the ages of T. rex is an interesting idea. However, i wonder if there may have been another species, based on an apparent hiccup in it’s ontogeny: http://accpaleo.wordpress.com/2010/08/21/just-a-thought/

By: Dave Hone

Dave Hone — Fri, 01 Apr 2011 14:34:34 +0000

Thanks for this Brian, nice stuff. And with a last bit of shameless self-promotion, there are lots more posts coming on this! I kinda have to milk it really don’t I?