determining species of North American stegosaurs
Kenneth Carpenter, 2010. Species concept in North American stegosaurs. Swiss Jour. Geosciences IN PRESS. ABSTRACT. The plated thyreophoran or stegosaurian dinosaur Stegosaurus armatus was named in 1877 by Marsh for fragmentary remains from the Morrison Formation (Upper Jurassic) of Colorado, USA. Subsequent discoveries from the same formation in Wyoming and Colorado (USA) have been assigned to separate stegosaurian genera and species, but most of these are no longer considered valid. More recently, a partial stegosaurian skeleton from Wyoming was named Hesperosaurus mjosi. However, the validity of this genus has been questioned recently, raising the question: how much osteological difference among stegosaur taxa is needed to separate genera from species? The question is examined vis-à-vis species and genus recognition in other dinosaurs, including iguanodonts, lambeosaurine iguanodontids, chasmosaurine ceratopsians, tyrannosaurid theropods, and diplodocid sauropods. The basis for taxonomic distinction is largely philosophical: if the species are morphologically distinct enough, they should be treated as separate genera. Based on these criteria, Hesperosaurus mjosi is a distinct taxon.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~STEPHAN PICKERING / Chofetz Chayim ben-AvrahamJewish dinosaurologist / Heretic spiritistTHE DINOSAUR FRACTALS PROJECT2333 Portola Drive # 4Santa Cruz, California 95062-4250IN PROGRESS: Mutanda Dinosaurologica: in memory of Samuel Paul Welles (9 November 1909--6 August 1997)IN PROGRESS: Dialects of a synaesthetic heart: poetics for Faline Pickering (23 January 1949--24 August 2008)IN PROGRESS: Alfred Russel Wallace's KING KONG: the semioptics of Willis O'BrienPARTNER IN THE UNIVERSE TO: FALINE PICKERING, MY BELOVED QUANTUM PISCESMEMBER 13853: Society of Vertebrate PaleontologyOne concept corrupts and confuses the others. I am not speaking of the Evil whose limited sphere is ethics; I am speaking of the infinite. -- JORGE LUIS BORGESYou never know what's comin' for you. -- QUEENIE in ERIC ROTH'S The curious case of Benjamin ButtonWhat if G-d didn't say it? -- BART EHRMANSeek the sacred with the ordinary. Seek the remarkable with the commonplace. -- REB NACHMAN OF BRATSLAVG-d is all that exists, but not all that exists is G-d. -- R. MOSHE CORDOVERO