Taxonomy Mammuthus meridionalis

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molar


the taxonomy of extinct elephants complicated 20th century, , in 1942, henry fairfield osborn s posthumous monograph on proboscidea published, wherein used various taxon names had been proposed mammoth species, including replacing mammuthus mammonteus, believed former name invalidly published. mammoth taxonomy simplified various researchers 1970s onwards, species retained in genus mammuthus, , many proposed differences between species instead interpreted intraspecific variation.


evolution

the earliest known members of proboscidea, clade contains modern elephants, existed 55 million years ago around tethys sea. closest known relatives of proboscidea sirenians (dugongs , manatees) , hyraxes (an order of small, herbivorous mammals). family elephantidae existed 6 million years ago in africa , includes modern elephants , mammoths. among many extinct clades, mastodon (mammut) distant relative of mammoths, , part of separate family mammutidae, diverged 25 million years before mammoths evolved. following cladogram shows placement of genus mammuthus among other proboscideans, based on characteristics of hyoid bone in neck:
































mammuthus meridionalis


since many remains of each species of mammoth known several localities, possible reconstruct evolutionary history of genus through morphological studies. mammoth species can identified number of enamel ridges (or lamellar plates) on molars: primitive species had few ridges, , number increased gradually new species evolved feed on more abrasive food items. crowns of teeth became deeper in height , skulls became taller accommodate this. @ same time, skulls became shorter front minimise weight of head.



skeletal restoration


the first known members of genus mammuthus african species m. subplanifrons pliocene, , m. africanavus pleistocene. former thought ancestor of later forms. mammoths entered europe around 3 million years ago. earliest european mammoth has been named m. rumanus; spread across europe , china. molars known, show had 8–10 enamel ridges. population evolved 12–14 ridges, splitting off , replacing earlier type, becoming m. meridionalis 2–1.7 million years ago. in turn, species replaced steppe mammoth (m. trogontherii) 18–20 ridges, evolved in eastern asia around 2–1.5 million years ago. columbian mammoth evolved population of m. trogontherii had crossed bering strait , entered north america 1.5 million years ago; retained similar number of molar ridges. mammoths derived m. trogontherii evolved molars 26 ridges 400,000 years ago in siberia , became woolly mammoth (m. primigenius).


a 2015 study of mammoth molars confirmed m. columbi evolved eurasian m. trogontherii, not m. meridionalis had been suggested earlier. confiemd 2016 genetic study of north american mammoth specimens.








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