STL Science Center

STL Science Center

08 January 2016

Geographic Challenge

In the course of history international borders have changed with an ebb and flow that some times makes sense from geographic and political changes (i.e. when rivers change and new countries are established over time) to conflict inspired changes (i.e. outcomes of war/treaties/purchases) and some times makes little to no sense at all (e.g. when rivers move and borders are retained). However things have come about in China, the province of Inner Mongolia within China's northern borders is south of the country of Mongolia and has lent itself to some confusions over locality descriptions in secondhand (or more) accounts of fossil discoveries. One prominent example is the discovery of a fossil hadrosaur originally described in 1933 by Charles Gilmore as a member of the established genus Mandschurosaurus Riabinin 1925. Gilmore's description named the animal Mandschurosaurus mongoliensis; thereby leading to some of the geographic confusion as mongoliensis means "from Mongolia". Predating the naming of Euhelopus (discussed last week) by four years, Mandschurosaurus is the first named genus of all Chinese fossils (considering only those properly described by scientific study). Gilmore's fossil was discovered, by all accounts, in Inner Mongolia in 1923 by George Olson. Olson was collecting the fossils for the United States National Museum (now: National Museum of Natural History or colloquially "The Smithsonian") at which Gilmore was lumbering through old Yale finds from the days of Marsh. This is important in the context of what Gilmore was doing at the time, because the fossil remains of M. mongoliensis were fragmented and retrieved from multiple locations. Gilmore's expertise with a wide variety of fossil material from Yale included greatly fossilized bones constituting partial specimens as well as the broken fragments that Marsh had gleaned over, ignored, or simply not gotten around to describing during his life (subsequent workers at Yale had not described all of the works being passed on to Gilmore either of course).

Gilmore pieced together what he could of this basal iguanadont or hadrosaur dinosaur and attributed it to the genus Mandschurosaurus and continued on with all of the other fossils on his plate. Over 60 years later those remains and others attributed to the species were reviewed by Dr. Michael K. Brett-Surman (then of Johns Hopkins, currently the Smithsonian; coincidentally he is the first Smithsonian employee to have ever conducted a PhD strictly on dinosaurs!) in an all encompassing review of hadrosaur dinosaurs. His analysis determined that Gilmore's Mandschurosaurus was in fact derived enough in its own right that it warranted its own genus. The type is now known as Gilmoreosaurus mongoliensis Gilmore 1933. This may confuse some as it appears that Gilmore named the dinosaur after himself, but he most certainly did not as the genus is actually attributed as Gilmoreosaurus Brett-Surman 1979. Since that time two other species have been assigned to the genus.
Attributed to a user calling him/herself Thesupermat

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