Heterodontosaurus Best Preserved Cast on Display
Awww-dorable!
This cutie is a cast of the best preserved #Heterodontosaurus, H. tucki, from the famous Stormberg Series in South Africa.
The 3’ skeleton was covered “...by a thin, very hard ferruginous layer which can be removed only with the aid of a small diamond saw.” I wonder how many hours it took to prepare this skeleton.
The skull was initially prepared and described in 1962, I suspect it took many years to get to the 1980 paper’s detail.
The authors note the genus name is “In reference to the differentiated dentition, unexpected in an ornithischian.” Until this beast all #dinosaurs were essentially homodont, having one kind of tooth shape in their mouth.
This skull allowed Hopson to move #Lycorhinus (I recently posted on it!) from #therapsid to #dinosaur. Crompton and Charig in 1962 argued this skeleton shows that the ”...main radiation of the Ornithopoda had taken place before Upper Triassic times.” This was an astounding statement, one that is still being resolve today.
The description, done in 1980 by Sant Luca, notes the animal was bipedal with a “slow quadrupedal progression,” that the hands were a “grasping organ,” and it had a forelimb with “powerful flexor musculature.” It apparently lacked a rigid tail. He notes it has resemblances with “...small Ceratopsia.”
Santa Luca threw shade, “...the carpus and manus... is completely inaccurate” at Bakker and Galton 1974, fig. 1H. He does so because their error led to very wrong conclusions. I am always bummed out when something like that happens, but science is self-correcting.
Santa Luca points out the challenges of animals like H. tucki, as it upended the at-the-time thinking that all bipedal ornithischians were Ornithopods. He points out it isn’t a #fabrosaurid, and #Microceratops, #Psittacosaurus, and #Pachycephalosaurus are bipedal sometimes or all the time.
He suggests using the presence of an obturator foramen, which should be viewed as a dervied structure, thus Ornithopoda to him were #ornithischians that possess the obturator process on the ischium. Are you down with OPP (Obturator Process Present)? I should dig in and see if this is still a thing 44 years later! :-).
#FossilCrates