The dinosaur thread

I was going to suggest that the dinosaurs on the island were the most common ones in the fossil record, but then I remembered being told by a professor that the common fossils usually come from the largest dinosaurs in the most fossil-friendly environments, and don't have that much to do with how many of that species were around at the time.

That being said, isn't Iguanodon the most common dinosaur in the fossil record?

Iguanodon has gone through a lot of reshuffling though, with many supposed "Iguanodon" specimens reassigned to new genera, so that's probably no longer the case. In fact, something like Confuciusornis (known from thousands of specimens) would almost certainly have it beat.

Re dinosaurs being reptiles: There is no debate that dinosaurs are phylogenetically reptiles. What is slightly more divisive is how the word reptile should be used (i.e.: whether it denotes a monophyletic group or not).

Warm blooded reptiles though.

IIRC, current scientific opinion is that "warm blooded" and "cold blooded" are inaccurate enough that they should be disused in favor of better alternatives.

Externally vs. Internally regulated. It's more accurate.

As well as constant vs. variable body temperature.

Anyone here know how much truth (if any) there is to the old "Spinosaurus was surprisingly lightweight" meme? Greg Paul seems to have supported it back in the day (he more recently suggested an estimate of 10 tonnes, which I'm also unsure of).

To my knowledge it was thinly built, but its length more than makes up for it, still making it the largest.

BTW, for all the recent aquatic adaptations this thing had...it wasn't quadrupedal. It just had short legs, it couldn't walk on all fours.

And I won't get too deep in the fact that this thing didn't eat small prey (the fish it ate were the size of great whites and dangerous prey)...

Feduccia (in press) argues that the presence of propatagia in maniraptorans supports a volant ancestry. Is this correct (regardless of whether maniraptorans are dinosaurs)?

Neecroooooo!

Bird Evolution: Discontinuities and Reversals. "Theropod dinosaurs, widely accepted as the ancestors of birds, do not show a step-by-step gradational change to Archaeopteryx, the first known bird. The vast majority of traits reverse themselves at least once in the cladistic sequence. Those traits that do change in a unidirectional manner often show large jumps in the sequence. Ironically, the most bird-like of theropods (including the much touted feathered ‘theropod,’ Caudipteryx), are now apparently confirmed (under evolutionary presuppositions) to be nothing more than ‘secondarily’ flightless descendants of Archaeopteryx! Theropods fail as stratomorphic intermediates, occurring much too late in the stratigraphic record to serve as the ancestors of birds. The course of volant (flying) bird evolution itself is also full of discontinuities and trait reversals. Late Mesozoic birds fail to display a smooth connection either backwards to Archaeopteryx or forward to modern birds."

Dont know if that answers your question, or not.

Aside from the fact that's a creationist site, the supposed avian characters of Caudipteryx have been repeatedly debunked.

London and its Museum of Natural History researched about Sophie And have come up with numbers about her body weight.

First things first, wow. Rude. You do not ask a lady for her weight, Museums.

Second, this 150 million years old Stegosaurus Stenops would have been about the size of a small rhino, and weighed about 1,6 tonnes.

"Sophie" is a unique specimen regarding the fact that over 80% of her skeletal structure was found basically intact.

wat a qt patootie.

The alleged dromaeosaurid Balaur has been reevaluated as a bird (Darren Naish is a coauthor).

I would like someone with scientific know-how to help answer this question about the most probable classification of a fictional dinosaur hybrid.

edited 24th Aug '15 10:23:20 PM by MarqFJA

I'd say infraorder Carnosauria, family Allosauridae or Carcharodontosauridae.

edited 25th Aug '15 4:15:58 AM by Spinosegnosaurus77

Any particular reasoning?

Mostly the skull.

... So just a particular skull structure automatically puts it in Carnosauria?

It looks more like a carnosaur skull than any other theropod, so yes.

... By "it", I meant the whole dinosaur. Just saying.

Skulls and teeth can give you tonnes of information about the rest of what an animal looked like and how it lived, even if you've not got much else to go on. The rest of the body won't help much if you don't have an example of the skull: heck, you probably won't have much of an idea what the thing ate, for starters — broad strokes, at best.

Many a "typical" carnivore body plan can turn out to belong to an opportunistic, primary scavenger with omnivorous leanings when you finally get a good set of choppers to look at. :/

Many species are only known through sparse fossil evidence, though. If you have to choose between teeth or ankles, you choose teeth every time. More info on the beast as a whole.

edited 26th Aug '15 4:39:54 AM by Euodiachloris

Yeah, but there is such a thing called convergent evolution. I'd think one should look at the whole thing if possible, and then decide which taxonomic grouping the species in question is most closely similar to.

The postcrania don't look uncarnosaurian to me.

Indominus is a mishmash of so many different animals (including a cephalopod) that classifying her makes no sense.

Why so? We have real-life examples of organisms that have had foreign DNA segments implanted into their genomes. And it's not like we classify organisms only based on their ancestry. Then there's the concept of hybrid species, of which the I. rex is essentially an example, albeit an artificial one that includes technically minor contributions from species that are taxonomically very distant from its the Tyrannosaurus rex base. And I addressed a particular issue with such contributions in the JW thread, BTW; to summarize, for all we know the geneticists didn't actually use cuttlefish and frog DNA, but rather simply modified portions of the I. rex genome to mimick the relevant portions of those animals' genetic code to give it the desired traits ^note any given gene is cross-compatible regardless of species, or even whether it's animal or plant, because a gene only codes for a protein, and it's the interaction of various proteins or their individual effect on the whole organism's system that is important.

edited 27th Aug '15 7:43:35 AM by MarqFJA