Voth
The Voth are an alien of the week race from the Voyager episode "Distant Origin". They are a typical example of how Star Trek writers have no clue how evolution works. The Voth are supposedly the descendants of an advanced species of dinosaurs that fled from Earth to escape the mass extinction event that killed off all of the other dinosaurs. They settled in the Delta Quadrant, where they "evolved" into a very humanoid species.
Voth Technology
Having been space travellers for millions of years, the Voth are technologically quite advanced. They have space ships the size of cities, transwarp drive, advanced cloaking technology (including personal cloaking devices), transporters capable of moving an Intrepid-class starship, and computer-cracking technology capable of breaking Federation computer security in seconds (granted, given the nearly non-existent computer security seen in Trek, this last ability isn't exactly saying much).
Culture
While the Voth are far more technologically advanced than the Federation, they aren't as far ahead as might be expected with a head start of many millions of years. Voth progression is in fact quite slow, largely because of cultural resistance to challenging "Doctrine", a dogmatic and inflexible body of law that defines -- among other things -- acceptable avenues of scientific and technological research. For instance, Voth Doctrine states that the species is native to the Delta Quadrant, and despite ample evidence that they originated on Earth, the scientist who suggested the "Distant Origin" theory was arrested, tried for heresy, and forced to recant.
Non-Plausibility
- An advanced civilization of dinosaurs living on Earth should have left some evidence of their presence that scientists would have found.
- A civilization capable of interstellar travel to escape the Cretaceous–Tertiary extinction event should have been able to alter the asteroid's course -- preventing the collision from happening at all -- with considerably less effort.