Everything about The Creodont totally explained
The
creodonts are an
extinct order of
mammals that lived from the
Paleocene to the
Miocene epochs. They shared a common ancestor with
carnivorans.
Creodonts were an important group of carnivorous mammals from 55 to 35 million years ago in the ecosystems of
Africa,
Eurasia and
North America. In
Oligocene Africa, they were the dominant predatory group. They competed with the
Mesonychids, and the
Entelodonts and ultimately outlasted them by the start of the Oligocene and by the middle of the
Miocene respectively, but lost ground to the
Carnivorans. The last genus went extinct 8 MYA, and carnivorans now occupy their ecological niches.
Evolution and taxonomy
Creodonts were considered ancestors to
Carnivora, but are now considered to have shared a common ancestor further back. They share with the Carnivora the
carnassial shear, scissor teeth that evolved to slice meat and gave both orders the tools to dominate the
niche. Some researchers argue that the creodonts represent a group of mammals of diverse biological ancestry that resemble one another via
convergent evolution, rather than being the descendants of a single common ancestor. Their origins lie at least as far back as the late
Cretaceous, though they didn't
radiate much until the
Cenozoic. Creodonts were the dominant carnivorous mammals from 55 to 35
MYA, peaking in diversity and prevalence during the
Eocene. By the mid
Oligocene, Creodonts supplanted both the
Mesonychids, and giant flightless predatory
birds entirely in
North America,
Eurasia and
Africa, and in turn, competed with their own relatives Carnivorans. The last genus,
Dissopsalis, went extinct about eight million years ago.
Habitat
The creodonts ranged across
North America,
Eurasia and
Africa, in forms that resemble those of modern carnivores. Amongst their number was
Megistotherium, which some argue was the largest mammalian land predator of all time, the size of a
bison and with a skull twice as big as a tiger's.
Megistotherium may have rivaled
Andrewsarchus mongoliensis in size. Their dominance over the early Carnivora, known as
miacids, began to wane after 35 MYA. The creodonts survived until 8 million years ago; the last form,
Dissopsalis, died out in
Pakistan.
Bears,
cats,
mustelids,
hyenas,
canids such as
wolves and other Carnivora now occupy the former creodont niches.
Reasons for extinction
It isn't known exactly why the Creodonts were replaced by Carnivora. It may be because of their smaller brains and
locomotion which was somewhat less energy-efficient (especially while running) and mostly
plantigrade. These subtle disadvantages may have been important over millions of years. The Creodont lumbosacral spine wasn't arranged as efficiently for running as in Carnivora. The arrangement of the teeth was also somewhat different. In the miacids (and so in the modern Carnivora), the last upper
premolar and the first lower
molar are the
carnassials, allowing grinding teeth to be retained behind for feeding on non-meat foods (the
Canidae are the closest modern analog to miacid dentition). In creodonts, the carnassials were further back - either first upper and second lower molars, or second upper and third lower molars. This committed them to eating meat almost exclusively.
In the most strictly carnivorous of modern Carnivora, the
Felidae, the second and third molars have disappeared completely, and the first upper molars behind the carnassials have become
vestigial. Modern cats thus eat plant food only incidentally.
Further Information
Get more info on 'Creodont'.
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