Everything about Carnivoramorpha totally explained
Carnivoramorpha are a
clade of
mammals that includes the modern order
Carnivora and its closest extinct relatives in the
Miacoidea (
Miacidae and
Viverravidae), but excludes the
creodonts. The order Creodonta are a sister
taxon to the Carnivoramorpha dating back 58.7 million years ago. The oldest carnivoramorphans are viverravids, and the oldest generally accepted viverravid is
Protictis dated at 63 million years ago.
Ravenictis from Canada may also be a carnivoramorphan and this would extend the date back to at least 65 million years ago.
Definition
The First International Phylogenetic Nomenclature Meeting (2004) states: “Modification of the upper fourth
premolar (P4) and lower first
molar (m1) as
carnassial teeth has been considered a
synapomorphy for carnivorans, here we follow a recent convention employing the name Carnivoramorpha for that clade and restricting the meaning of the widely known name Carnivora to the smaller
crown clade delimited by the
extant species regarded as carnivorans. Accordingly, Carnivoramorpha is here defined as the smallest clade containing the earliest organism to have the P4/m1 carnassial shear synapomorphic with that in
Felis catus. Morphological and molecular evidence indicates that the carnivoran
Aeluroid,
Cynoid and
Arctoid clades share an exclusive common ancestry. Species representing these three major carnivoran clades are used as specifiers in the definition of Carnivora, which is here defined as the smallest clade containing
Felis catus,
Canis familiaris and
Mustela erminea.”
Evolution
When Carnivoramorpha first emerged in the
Paleocene they were not the only group of
terrestrial meat-eating mammals present. The Creodonta, comprised of the
Oxyaenids (robust, short-limbed wolverine forms) and the
Hyaenodontids (slender-limbed, semi-
cursorial forms), were also present and were well on their way toward their maximum speciation, which occurred in the middle
Eocene era (Stiles, 2005). Judging from their
dentitions, many were specialized meat eaters and must be included in any study addressing the evolution of
mammalian carnivory. In North America few creodonts survived past the
Eocene, and all were extinct by the late
Oligocene. The taxonomic decline of Creodonta at the end of the Eocene coincided with the beginning of the speciation and radiation of the Carnivora, and the origination of most modern carnivore families. Regardless of whether this was taxonomic displacement or replacement this pattern has generated the hypothesis that the diversification of carnivorans was suppressed by the incumbent creodonts early in their history.
The first carnivores likely arose from a small insectivorous mammal found in the middle Eocene era, a time of rapid differentiation for mammalian species. The earliest known members of the carnivores are rarely found as fossilized bones; most often they're recovered strictly as tooth samples and partial jaw fragments. These pioneering species are classified in the
Miacidae clade, which is morphologically separable into two lineages, the Viverravines and the Miacines. Both members of these lineages display dental features that are typically characteristic of carnivores, shearing teeth known as carnassials along with the presence of a
transverse jaw hinge. The main difference in these early Miacidae members is found in their dentition, the Miacines resemble the
caniforms while the Viverravines resemble the
feliforms.
Classification & Phylogeny
Clade Carnivoramorpha (basal to Carnivora but without Creodonts)
- Superfamily †Miacoidea
- Family †Miacidae
- genera: Chailicyon, Eostictis, Ictognathus, Miacis, Miocyon, Oodectes, Palaearctonyx, Paramiacis, Paroodectes, Prodaphaemus, Quercgyale, Tapocyon, Uintacyon, Vassacyon, Vulpavus, Xinyuictis, Ziphacodon
- Family †Viverravidae
- Order Carnivora
Carnivoramorpha
|?- †Aelurotherium
|?- †Eosictis
|?- †Elmensius
|?- †Intyrictis vanvaleni
|?- †Notoamphicyon
|?- †Ravenictis krausei or cimolestan
|?- †Vishnucyon
`--+-- †Miacoidea (paraphyletic)
`--+-- †Viverravidae [Viverraroidea]
`--+-- †Miacidea (paraphyletic)
`--+-- †Oodectes
`--+-- †Vulpavus
`--+-- †Miacis
`--+--+-- †Tapocyon
| `--+-- †Miacis sylvestris
| `-- †Prohesperocyon wilsoni
`--+-- †Quergygale angustidens
`-- †Nimravidae? (very unstable position with respect to Carnivora -
unresolved as of August 2007)
`-- Carnivora
`-- Caniformia
`-- Aeluroidea
Further Information
Get more info on 'Carnivoramorpha'.
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