[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
OVIRAPTOROSAURIA! Part Three [Taxa and Phyllogenetics - Oviraptorids]
WE INTERRUPT THIS REGULARLY-SCHEDULED DINOSAUR LIST DISCUSSION TO BRING YOU THE FOLLOWING:
After the Caenagnathidae, Jaime waits for a while, and then, relaxing a bit as the headache passes, launches into the last bit of the Oviraptorosauria findings, by far the more complete part:
"It was *Oviraptor philoceratops" first, whose name means 'ceratopsid-living egg snatcher', a misnomer based on an assumption by Osborn (1924a) that the eggs the type was found near were protoceratopsid eggs, and not the theropod's own. The type was about 6-7 feet in length or 1.8-2.1 meters, and weighed almost 175 pounds, or 80 kilograms (Paul, 1988, drops the mass to about 75 kilograms, making a little over 160 pounds). The ilium is arched over the acetabulum, which is odd considering all other *Oviraptor* ilia are not; the same goes from the count of cervical vertebrae, where I see about 9, Barsbold (1975, 1997) suggests 10-11; a new *Oviraptor* skeleton with completely intact neck has 13, and it doesn't seem as if the type's skull was separated from the neck, for bits and pieces of the neck form a line right to the back of the skull, and the skull itself is intact, and doesn't show any movement from place of death/burial. Finally, the skull has a raised, medially-ridge p!
arietal, of the type seen in the skull of *Rinchenia*, suggesting the skull, absent all dorsal elements but the parietals, had a skull reaching back to the rear of the skull; all other crested "Oviraptor" skulls show a lack of ridged parietals of this type, and the crest only goes back to the frontals. What this suggests is that the type of *Oviraptor* and the skull of GI 100/42 (by far the most popular skull illustrated) belongs to a different species, as does the new skeleton with complete neck, a juvenile of sub-adult proportions lacking a crest that may be a female of a new genus (the few preserved caudals show the forward-set haemal-arches as in Sue and crocodiles). The animals are all from the Djadochta Formation of Mongolia and China, most famously of Shabarakh Usu (the Flaming Cliffs) and Ukhaa Tolgod, as well as a Chinese site, Bayan Mandahu, all of which are about Cenomanian in age, early at least, and late at most, parallel to the Judithian strata of North America."
Jaime sighs, and says that that one was really unexpected, and provoked the whole study. The other taxa are apparently less confusing, and led to insight into behavior:
"The next largest was *Rinchenia mongoliensis*, whose name means 'Rinchen's from Mongolia', and was about 6-7 feet long or 1.8-2.1 meters long, and was relatively light-bodied at 120 pounds or so, or 55 kilograms. The dome-shaped crest was perhaps the most dramatic feature of this animal, and along with the presence of lateral mandibular foramina on the surangulars (a pair on each side) is quite different from the other oviraptorid taxa. He was also Djadochta in strata, Cenomanian, and inhabited the same environment as *Oviraptor*.
"This one is *Ingenia yanshini*," Jaime says, showing a restoration of a small, round-headed animal, vaguely bird-like, with huge eyes. "Her name means 'Yanshin's Ingen-khobur [oviraptor]', and was short, but heavy-set, stocky, like the Hell Creek *Caenagnathus*, and measured only 5 feet or 1.5 meters but weighed close to 100 pounds or 45 kilograms. It's not the skull with its prominent cheekbone, but the hands, with the first finger's claw really larger than the other two fingers, claws and all. Oddly, the third digit's phalanges were all of almost the same length, and the claw, too, which along with the 'thumb' remains a distinct classification for the Ingeniinae, with all other taxa outside in the Oviraptoridae. She was found in the upper Djadochta and Barun Goyot Formations of Mongolia, and in China from the Iren Dabasu Formation, which was similar to the Barun Goyot; the Barun Goyot and Iren Dabasu Formations were later than the Djadochta, which means *Ingenia* could've!
been Maastrichtian, at least earliest. There's a second skull, too, that only 5 inches or 160 mm, which isn't very big, that's really long and low compared to the other skull, but it's not really completely together, whether it came apart in preservation, or was a youngster. Superficial resemblance to the round skull is in the orbit and lower infratemporal, but I've found little else to connect them, but I don't rule out ontogenetics (characters change with age). Strange. But it _might_ be a new species of *Ingenia*, and even more hesitant am I to suggest a generic difference, if at least to get it on the books."
It's almost as if Jaime is trying to name new dinosaurs, but accordingly, the answer was: "I'm just trying to cover all the bases, just in case; I know I'm jumping a little on some of this, but it seems reasonable."
The next taxon is the last, and smallest.
"This one is tiny *Conchoraptor gracilis*, whose name means 'slender shell-snatcher', and was only 4-5 feet long or 1.2-1.5 meters, really tiny, and was the weight of *Caenagnathasia*, or maybe a little heavier. Strangely enough, *Conchoraptor* has a hand more similar to *Ingenia* than to *Oviraptor*, with long digits and a large thumb, short second and third fingers (but still longer than the thumb) and the third digit had the same phalangeal proportions as *Ingenia*; the claws of both taxa are really strait, straiter than *Oviraptor's* claws. Stranger is the foot, which has curved, hook-like claws more like dromaeosaurs and such theropods than other oviraptors and ornithomimids. It suggests to me that he was a climber. He also possessed a nasal inflation like the nose-crested *Oviraptor*, suggesting a connection that obscures his phyllogenetic position [see below]. He was from the Barun Goyot, at Herem in Mongolia."
| +--+--Oviraptor "type"
| |--+--Oviraptor "long neck"
| | +--Ingenia
| |--+--Chirostenotes sternbergi
| | +--+--Chirostenotes pergracilis
| | |--Chirostenotes sp.
| | +--Elmisaurus rarus
| +--+--Oviraptor "type"
| | | "long neck"
| | +--Ingenia
It was with a small smile that Jaime Headden finishes. There was also mention of a website that has all this information, called:
Jaime A. Headden
P.S.: this site was supposed to be up before the end of the month, but by the time I put it up, on May 30, there were problems, and it has taken this long to fix them.
DO YOU YAHOO!?
Get your free @yahoo.com address at Yahoo! Mail.