# Are dinosaurs reptiles or not? **URL:** \ **Category:** Factual Questions\ **Created:** [October 11, 2003, 2:56am UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786 "2003-10-11T02:56:29Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![umop\_ap\_sdn](https://avatars.discourse-cdn.com/v4/letter/u/dbc845/32.png) [@umop\_ap\_sdn](https://boards.straightdope.com/u/umop_ap_sdn)\ **Post date:** [October 13, 2003, 7:37pm UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786/21 "2003-10-13T19:37:53Z")
Oh and **Floater** , if apes are monkeys then humans are monkeys too. 😉 ---
**Author:** ![j.c](https://avatars.discourse-cdn.com/v4/letter/j/73ab20/32.png) [@j.c](https://boards.straightdope.com/u/j.c)\ **Post date:** [October 13, 2003, 8:24pm UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786/22 "2003-10-13T20:24:33Z")
Well, some of our classifications, based on observable features, are looking a little off now that we can observe the genes. Sometimes the environment (for example, marsh vs. grassland) will make you more than our kinfolk will. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [October 13, 2003, 10:12pm UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786/23 "2003-10-13T22:12:26Z")
> [@](#): > > \*Originally posted by aryk29 \* > \*\*Is Bakker suggsting that the Saurischia is paraphyletic, and that the sauropods are closer relatives of ornithischians than of theropods? Is it true that I am not the only one to suspect that to be the case? \*\* I don’t think Bakker was suggesting that, but rather simply sticking all the quadrupeds together and all the bipeds together. That, and Bakker’s always come across (to me, at least) as something of a loon, anyway… _The Dinosaur Heresies_ was written around the same time as Gauthier’s (and others’) cladistic re-examinations of the Dinosauria; such re-examinations reaffirmed that Saurischia and Ornithischia are, indeed, monophyletic, and that sauropods are members of the former. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 14, 2003, 2:56am UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786/24 "2003-10-14T02:56:24Z")
Given that the only categories considered in cladistics are those of “organism together with all its decendants”, where does that leave the prokaryotes? All eukaryotes are decended from prokaryotes, so any clade which contained all prokaryotes would necessarily contain all other organisms, as well. So how does cladistics refer to prokaryotes, as a group? ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [October 14, 2003, 5:07am UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786/25 "2003-10-14T05:07:37Z")
Well, the issue is most easily resolved by simply not adhering to the eukaryote / prokaryote dichotomy. If eukaryotes descended from prokaryotes, but are considered separately, then “prokaryotes” (as typically defined) is necessarily paraphyletic, thus not a natural clade. Generally speaking, prokaryotes are thought to have descended from an Archaeobacterial ancestor, somtime prior to the Aerchaeobacteria / Eubacteria split. See [here](http://www.gly.uga.edu/railsback/1122Lifegram.html) for a visual. Note, however, thast the monophyly of Archaea itself is also questionable (things do get a little fuzzy when looking back towards the origins of life, after all); see the [Tree of Life](http://tolweb.org/tree?group=Life&contgroup=) page. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [October 15, 2003, 12:18am UTC](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786/26 "2003-10-15T00:18:40Z")
As I read this stuff (with much interest) I have to keep reminding myself that “split” doesn’t mean the same here as it does in real life. Not like an actual branch of an actual tree. In this thread’s context “split” means “diverged from over a heck of a long time”. Thanks, that _Tree of Life_ is a great page. Carry on. 🙂 [Previous page](https://boards.straightdope.com/t/are-dinosaurs-reptiles-or-not/206786.md?page=1)