Ursus maritimus tyrannus

Ursus maritimus tyrannus (lit. 'bodi na teku mai tiranoni') wani nau'i ne mai rikitarwa na Beyar polar.

 Bincike 
Masanin burbushin halittu na Finnish Björn Kurtén ne ya ba da sunan nau'ikan beyar polar a cikin 1964, bisa ga wani ɓangaren ulna guda ɗaya da aka samo a cikin dutsen Thames a Kew Bridge, London. An kuma gano burbushin tare da bison steppe (Bison priscus), reindeer (Rangifer tarandus) da wolves (Canis lupus).

An fassara samfurin don wakiltar babban mutum. An kiyasta ulna ya kasance   in) tsawo lokacin da ya cika- don kwatanta, ulnae na zamani na subadult polar bear suna da 36-43  in) tsawon.Kurtén, B. (1964). "The evolution of the polar bear, Ursus maritimus Phipps". Acta Zoologica Fennica. 108: 1–26. hdl:10138/37762. An rubuta ulna a farkon Weichselian na Late Pleistocene (~70kya). Crockford, Susan J. (2022-05-06). "Polar Bear Fossil and Archaeological Records from the Pleistocene and Holocene in Relation to Sea Ice Extent and Open Water Polynyas". Open Quaternary. 8 (1): 7. doi:10.5334/oq.107. ISSN 2055-298X. Daga cikin samfurori 16 da aka gano a matsayin bears na Pleistocene, wannan shine kawai burbushin da aka danganta ga wannan nau'in.

 Rikici 
A cikin 2008 Charles Harington ya bayyana cewa gano beyar polar yana da kyau bisa ga canje-canjen matakin teku da yanayin kankara a Tekun Arewa na lokacin. Koyaya ya kuma lura cewa Andy Currant na Gidan Tarihi na Halitta, London ya yi imanin cewa burbushin yana wakiltar babban beyar launin ruwan kasa maimakon beyar polar, yayin da tarin dabbobi daga wasu shafukan Burtaniya na zamani, wanda kuma bison, reindeer da wolves suka mamaye, suna adana manyan beyar launin toka kamar beyar Kew Bridge.

Ra'ayin Andy Currant cewa burbushin Kew Bridge na wani beyar launin ruwan kasa ne, kodayake an ambaci shi a cikin hira ta BBC ta 2007 da kuma a cikin binciken daga 2009 da 2022, yana jiran tabbatar da kimiyya.

 Manazarta