And the last of my Star Trek entries into the Geology and Dinos in Pop Culture is perhaps the greatest dinosaurian related episode of Star Trek to date. The episode is from Star Trek: Voyager, Season 3, Episode 23, entitled "Distant Origin".
This clip above is just a small portion of the episode, in which I highly recommend watching the whole thing if possible. In the episode, the crew of the Voyager are faced with the Voth. A species that, after some genetic determination, evolved from hadrosaursians and somehow ended up across the galaxy into the Delta Quadrant. Their supposition was that this hadrosaurian species survived the extinction of the dinosaurs and were isolated on an island, where eventually they evolved space-faring technology to somehow eventually leave Earth and end up across the cosmos. The best part is when they start researching the history of the Voth, leading them to Eryops, "from the Devonian era".
|Eryops from the Star Trek: Voyager episode "Distant Origin"
Their reconstruction of Eryops though, does not actually resemble the current reconstructions (pictured below). Nor is it from the Devonian, having been found in Permian deposits over 100 million years later. However, this reconstruction looks amazingly like a pelycosaur, like Dimetrodon, just without the sail.
|Eryops reconstruction from Britannica.
Eryops was an amphibian, and was supposed to stand in on Voyager as the "last common ancestor of cold-blooded and warm-blooded organisms." My assumption is that they were looking for the split between mammals and reptiles. However, that is not entirely an accurate thing, since mammals evolved much later. What we need to search for is the split between Synapsids (the group that evolved into and includes mammals) and Diapsids (the group that includes crocodilians, dinosaurs, and birds). Both of these groups fall under the classification of amniotes.
|Dimetrodon skeleton. Image courtesy of ScienceSourceImages.
|The "most highly evolved" dinosaur according to Star Trek: Voyager.
|Evolution of the Voth from their Parasaurolophus ancestors
|Reconstructions of the small Cretaceous theropod Stenonychosaurus inequalis and a hypothetical dinosaurid (Russell and Séguin, 1982)