Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: Sanannen masanin ilimin halittu Barnum Brown ya dawo da kwanyar duckbill a 1915 don Gidan Tarihi na Tarihi na Tarihi (AMNH 5836) daga Red Deer River na Alberta, kusa da Steveville. Ya bayyana samfurin a cikin 1916 a matsayin sabon jinsi, Prosaurolophus. Zaɓin sunan Brown ya fito ne daga kwatankwacin jinsin Saurolophus, wanda ya bayyana a 1912. Saurolophus yana da irin wannan amma ya fi tsayi kuma ya fi kama da kaifi. Ƙwallon ya lalace da ƙuƙwalwa kuma an sake gina shi ba da daɗewa ba, amma an sami raguwa mafi kyau wanda ya nuna ainihin siffar; daya shine kusan cikakkiyar kwarangwal da kwanyar, wanda William Parks ya bayyana a 1924. An san mutane ashirin zuwa ashirin da biyar ga wannan nau'in, gami da kwanyar bakwai tare da aƙalla wasu ragowar kwarangwal. Nau'in na biyu, P. blackfeetensis, ya dogara ne akan samfurin a cikin Gidan Tarihi na Rockies (MOR 454), wanda wani masanin ilimin lissafi mai suna Jack Horner ya bayyana. Wannan samfurin, da sauran mutane uku ko hudu, an samo su a Glacier County, Montana. A wannan yanayin, an gano burbushin a cikin kwandon kwarangwal na Prosaurolophus, wanda ke nuna cewa dabbobin sun rayu tare aƙalla wani lokaci. An fassara kwandon kwarangwal a matsayin mai nuna ƙungiyar dabbobi waɗanda suka taru kusa da tushen ruwa a lokacin fari.Horner ya bambanta nau'ikan biyu ta hanyar cikakkun bayanai na crest. Ya fassara P. blackfeetensis a matsayin yana da tsayi, fuska mafi tsayi fiye da P. maximus, tare da hawan da ke ƙaura baya zuwa idanu yayin girma. Binciken da aka yi kwanan nan sun yi la'akari da bambance-bambance a matsayin wanda bai isa ba don tallafawa nau'i biyu.  Tambaya: A wane kogi ne Brown ya gano kwanyar duckbill?
Kogin Red Deer