Bactrosaurus

Name: Bactrosaurus ‭(‬club lizard‭)‬.
Phonetic: Bak-tro-sore-us.
Named By: Charles W.‭ ‬Gilmore‭ ‬-‭ ‬1933.
Synonyms: Cionodon kysylumensis‭?
Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Ornithischia,‭ ‬Ornithopoda,‭ ‬Hadrosauroidea.
Species: B.‭ ‬johnsoni‭ (‬type‭)‬,‭ ‬B.‭ ‬kysylumensis‭?‬,‭ ‬B.‭ ‬prynadai.
Diet: Herbivore.
Size: About‭ ‬6‭ ‬meters long.
Known locations: China‭ ‬-‭ ‬Iren Dabasu Formation,‭ ‬Zouyun Formation.‭ ‬Kazakhstan‭ ‬-‭ ‬Dabrazhin Formation.‭ ‬Mongolia‭ ‬-‭ ‬Baynshire Formation.
Time period: Cenomanian to Campanian of the Cretaceous.‭
Fossil representation: Several individuals,‭ ‬including adults and juveniles.

       Bactrosaurus is one of the earliest hadrosauroids known from Asia,‭ ‬and also one of the best known.‭ ‬Bactrosaurus still had three stacked teeth for each tooth in the maxilla,‭ ‬an iguanodont feature that reveals the ancestry of the genus.‭ ‬However,‭ ‬Bactrosaurus also has a number of hadrosauroid features,‭ ‬particularly those of lambeosaurines‭ (‬hollow crested like Lambeosaurus‭)‬.‭ ‬For most of its early taxonomic life,‭ ‬Bactrosaurus was reconstructed as being crestless.‭ ‬However,‭ ‬study of one Bactrosaurus skull seems to show the early development of a bony crest.‭ ‬This could be a further indicator for Bactrosaurus being ancestral to lambeosaurines.‭
       Some Bactrosaurus skeletons show the presence of tumours,‭ ‬mostly benign,‭ ‬but also cancerous.‭ ‬Some later hadrosaurs such as Edmontosaurus and Brachylophosaurus also show the common development of tumours,‭ ‬which has led to speculation that at least some genera of hadrosaurs had a genetic predisposition towards developing tumours and possibly even cancer.
       A former species of Cionodon,‭ ‬C.‭ ‬kysylumensis is often included as a species of Bactrosaurus.

Further reading
-‭ ‬On the dinosaurian fauna of the Iren Dabasu Formation.‭ ‬-‭ ‬Bulletin of the American Museum of Natural History‭ ‬68‭(‬2-3‭)‬:23-78.‭ ‬-‭ ‬Charles W.‭ ‬Gilmore‭ ‬-‭ ‬1933.
-‭ ‬Some results of the studies of the Upper Cretaceous dinosaurian fauna from the vicinity of the station Sary-Agach,‭ ‬South Kazakhstan.‭ ‬Problems of Paleontology‭ ‬4:125-135.‭ ‬-‭ ‬A.‭ ‬N.‭ ‬Riabinin‭ ‬-‭ ‬1938.
-‭ ‬Epidemiologic study of tumors in dinosaurs.‭ ‬-‭ ‬Naturwissenschaften‭ ‬90‭ (‬11‭)‬:‭ ‬495‭–‬500.‭ ‬-‭ ‬B.‭ ‬M.‭ ‬Rothschild,‭ ‬D.‭ ‬H.‭ ‬Tanke,‭ ‬M.‭ ‬Helbling II‭ & ‬L.‭ ‬D.‭ ‬Martin.‭ ‬-‭ ‬2003.





----------------------------------------------------------------------------

Random favourites