Saturday, July 05, 2008

Dino Diagnosis of the Day

Time for another edition of Dino Diagnosis of the Day! Remember, these diagnoses are taken directly from the original publication, and any pertinant names have been removed. This is an old dinosaur, so you might not know it right off the bat! And awaaay we go!

"A bipedal saurischian of small size, with strong hind limbs and small forelimbs. The bones are hollow, but with rather thick walls. The lower jaws are long, about equal to the length of the femur, indicating a skull quite large in relation to the size of the body. The theeth are thecodont. There were probably about 23 to 25 presacral vertebrae (the anterior ones are missing), three sacrals and a long tail with perhaps 40 or more vertebrae. The centra of the vertebrae are platycoelous and constricted in their mid-portions. The vertebrae have strong diapophyses, with buttresses beneath them, and rather short, heavy neural spines. The ilium is deep and short, its iliac crest being abbreviated, and produced posteriorly. The acetabulum is deep within the ilium and its upper margin forms a shelf to take the thrust of the femur against it. The pubis is long, about two-thirds as long as the femur, broad and platelike, and the two pubes are joined along their midlines by a long symphysis. The ischium is broad proximally, but narrows to a rodlike bone in its more distal portions. The bones of the pelvis seemingly do not unite firmly, but rather are joined by restricted facets, so that the central portion of the acetabulum is open. The femur is a curved, heavy bone, the head strongly set off from the shaft, with no lesser trochanter, but with a strong fourth trochanter. The tibia is strong and the tibia and fibula are elongated, being slightly longer than the femur. The astragalus and calcaneum are obviously separate, but evidently in life were closely appressed to the limb bones."

It just keeps going on like this. The paper has no short "diagnosis" section, thus I've left off the rest of the paper. But this should be enough to get you started.


Neil said...

Hmmm... "old", small, long skull, hollow bones- I'm going with Coelophysis er, Syntarsus, er Megapnosaurus (bless you). The "small forelimbs" bit doesn't quite seem to fit though...Procompsognathus? Man, so many of those descriptions could halfway fit any small theropod, boring little beasties aren't they?

Zach said...

You got that right. I'll give you another hint, though. Late Triassic beastie. Colbert, 1970.

Christopher Taylor said...

Is it Staurikosaurus?

Zach said...

Yep! Chris for the win!