Nyasasaurus parringtoni, a dinosauriform from the middle Triassic, may or may not be the oldest dinosaur known to science. It was originally dug up in the 1930’s, but a proper description has taken until now to be published.
The description, in Biology Letters (
open access well it was when I originally opened the tab – pdf here), is very conservative about claiming the “earliest dinosaur” title – they repeatedly insist that the fossil is merely “either the earliest known member of, or the sister–taxon to, Dinosauria.” This conservatism has apparently rather confused Mr Brian Thomas, as he alleges in his article World’s Oldest Dinosaur Fossil? that it’s all an evolutionary attempt to save face.
The previous record holder for oldest dinosaur was Eoraptor lunensis, at 231 million years old. Nyasasaurus is more than 10 million years older, at 243 million – only 9 million years after the mass extinction that began the Triassic, the largest in history. The fossil also conveniently comes from a period of dinosaur evolution we know very little about, and according to a Nature News article the find is significant whether or not it is truly a dinosaur:
Michael Benton, a palaeontologist at the University of Bristol, UK, agrees that Nyasasaurus sits near the base of the dinosaur family tree. “The authors have taken a properly conservative stance in not being 100% certain it’s a dinosaur,” Benton says, but the discovery nonetheless confirms an earlier origin for dinosaurs.
According to Thomas:
Clearly, the uncertainties arise “given its age,” but Nyasasurus’ age is based on evolutionary belief, not science. Within this scheme, true dinosaurs should not be found this far below other fully formed dinosaurs because they were not yet supposed to have evolved.
The researchers are uncertain as to whether or not it is a dinosaur, what pre-dinosaurs may have looked like, or how this dinosaur—or most others found in congruent rock layers—relates to other dinosaur forms within evolutionary assumptions.
All these uncertainties arise from evolutionary doctrine, not from dinosaur data.
There are two aspects to Thomas’ thesis: first, as he says above, that the “uncertainties arise from evolutionary doctrine”, and second that the uncertainty is being promoted because the find doesn’t fit evolutionary expectations.
The second can be quickly dealt with. As the paper says:
The occurrence of a late Anisian [the geologic period which this fossil comes from] ‘stem’ dinosaur or true dinosaur has previously been predicted by the sister–taxon relationship with the Middle–Late Triassic silesaurids.
This is the very opposite of a discovery that goes against what was expected. Thomas also says:
The study authors compared the humerus bone with others, finding that it best matches theropods—dinosaurs with lizard-like hips and three toes. According to the Natural History Museum, a well-known dinosaur that’s attributed to much “younger” rock layers “is the early dinosaur Eoraptor, which Nyasasaurus may have looked like.” If it looks like a theropod, why not just call it a theropod?
Clearly that would not fit evolutionary teaching, which predicts that pre-theropod ancestors (an uninhabited category) should be found below theropods, and that even more generalized pre-dinosaurs should be found below the pre-theropods in Nyasasaurus layers.
Instead, they got a well-formed theropod at the very bottom of the dinosaur fossil record.
There are a number of problems in these three paragraphs. Firstly, so far as I can tell it is not the humerus that would tie Nyasasaurus the theropods. Instead:
[T]he referred specimen bears two character states in the cervical vertebrae consistent with, but not exclusive to, theropod dinosaurs (deep fossae lateral to the neural canal in anterior view, deep lateral fossae).
“Consistent with, but not exclusive to” – that’s not really enough to say that the fossil is a theropod, especially when there are only two of them, and certainly not to call it “well formed” (whatever that would mean). The reason why the classification of this fossil is so difficult is a combination of the “fragmentary nature of the find” and the general lack of examples of what early dinosaurs of the time looked like. Most of the features described seem to be of the “dinosaurs have it, but so do some other things” variety. There are only a small handful that are apparently unique to dinosaurs, but it’s worth remembering that this fossil splashes down in a dark spot. There might have been an unknown non-dinosaur – but very closely related to dinosaurs – lineage to which this animal belonged that shared these features with their famous cousins. Caution is well placed here.
This lies at the opposite extreme to the Darwinius masillae business, which was as much hype as science if you remember. So far as I am aware no documentaries are currently in the offing about Nyasasaurus, though it mightn’t have been all that hard to persuade someone to do so. There is a genus called Revueltosaurus that was originally believed to be an early dinosaur based on its teeth, but since more of it has been discovered this is no-longer the case. Caution is well placed here.
Nevertheless, Thomas says:
So, to keep evolution’s plausibility, the Current Biology authors nursed the idea that Nyasasaurus could have been almost a dinosaur despite its perfectly dinosaurian anatomy.
Again, this is the opposite of the truth. For once, at least, he tries to give his own explanation of a finding that he has dissed. It just gets funnier and funnier:
In contrast, how well would the creation and Flood model of earth history and rock layers explain Nyasasaurus?
First, as a beast of the earth created on Day Six of the world, it should already be in a recognizable dinosaur form—and it is.
Second, as a creature that drowned in the Flood of unprecedented catastrophe, instead of scavenged or rotten on earth’s surface, its remains had a chance to be fossilized—and they were.
Third, as a creature that may have lived in a swampy environment—not a sea creature nor a dry land walker—it was buried above layers that contain mostly sea creatures deposited earlier during the Flood.
I can only shake my head at that.