Cimolesta

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Cimolesta
Temporal range: ~80–28.4  Ma
Palaeosinopa.jpg
Palaeospinopa from Wyoming Eocene
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Clade: Eutheria
Order: Cimolesta
McKenna 1975
Subgroups

Cimolesta is an extinct order of non-placental eutherian mammals. [2] Cimolestans had a wide variety of body shapes, dentition and lifestyles, though the majority of them were small to medium-sized general mammals that bore superficial resemblances to rodents, lagomorphs, mustelids, and marsupials.

Several groups have previously been suggested to have descended from the Cimolesta: the Pholidota (which would have been regarded as a suborder of Cimolesta), the Creodonta, and the Carnivora. The origins of the enigmatic Dinocerata have been suggested to lie within the Cimolesta as well. However, recent studies have revealed that cimolestans are more likely to be basal, non-placental eutherians, with no living descendants. [2]

Some experts had placed the pangolins within Cimolesta, though the current consensus is that the pangolins should be placed within their own order, Pholidota, as a sister taxon to Carnivora within Ferae. [3] [4] Some have also placed the enigmatic family Ptolemaiidae within Cimolesta, also due to similarities between dental and skull anatomies with those of Pantolesta. If the ptolemaiids were indeed cimolestids, then Cimolesta would have ranged from the Late Cretaceous to the early Miocene, when the last ptolemaiid, Kelba , disappeared in Eastern Africa. However, more thorough studies suggest that the ptolemaiids were more probably afrotheres related to aardvarks, tenrecs and golden moles. [5] [6] If one ignores the ptolemaiids as afrotherians, then the last, unequivocal cimolestids, the pantolestids Gobiopithecus and Kiinkerishella , died out during the Late Eocene or early Oligocene.

The cimolestid Procerberus may have been closely related to Taeniodonta. [7] [8] [9] [10] [11] Procerberus was the largest cimolestid and different species may be closer to conoryctid taeniodonts and others to stylinodontine taeniodonts. However, Procerberus has been found by cladistic analysis to be outside of a Taeniodonta + Alveugena carbonensis, with Procerberus grandis being closer to that clade than to other Procerberus species. [8]

Related Research Articles

<span class="mw-page-title-main">Placentalia</span> Infraclass of mammals in the clade Eutheria

Placental mammals are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less developed young which are then nurtured for a period inside the mother's pouch. Placentalia represents the only living group within Eutheria, which contains all mammals more closely related to placentals than to marsupials.

<span class="mw-page-title-main">Eutheria</span> Clade of mammals in the subclass Theria

Eutheria, also called Pan-Placentalia, is the clade consisting of placental mammals and all therian mammals that are more closely related to placentals than to marsupials.

<span class="mw-page-title-main">Afrotheria</span> Clade of mammals containing elephants and elephant shrews

Afrotheria is a superorder of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews, otter shrews, tenrecs, aardvarks, hyraxes, elephants, sea cows, and several extinct clades. Most groups of afrotheres share little or no superficial resemblance, and their similarities have only become known in recent times because of genetics and molecular studies. Many afrothere groups are found mostly or exclusively in Africa, reflecting the fact that Africa was an island continent from the Cretaceous until the early Miocene around 20 million years ago, when Afro-Arabia collided with Eurasia.

<span class="mw-page-title-main">Theria</span> Subclass of mammals in the clade Theriiformes

Theria is a subclass of mammals amongst the Theriiformes. Theria includes the eutherians and the metatherians but excludes the egg-laying monotremes and various extinct mammals evolving prior to the common ancestor of placentals and marsupials.

<span class="mw-page-title-main">Condylarthra</span> Grouping of extinct mammals

Condylarthra is an informal group – previously considered an order – of extinct placental mammals, known primarily from the Paleocene and Eocene epochs. They are considered early, primitive ungulates. It is now largely considered to be a wastebasket taxon, having served as a dumping ground for classifying ungulates which had not been clearly established as part of either Perissodactyla or Artiodactyla, being composed thus of several unrelated lineages.

<span class="mw-page-title-main">Ferae</span> A clade of mammals consisting of carnivorans and pholidotes

Ferae is a mirorder of placental mammals from grandorder Ferungulata, that groups together clades Pan-Carnivora, which includes modern carnivorans, and Pholidotamorpha, which includes pangolins.

<span class="mw-page-title-main">Taeniodonta</span> Extinct order of mammals

Taeniodonta is an extinct order of eutherian mammals, that lived in North America and Europe from the late Cretaceous (Maastrichtian) to middle Eocene.

<i>Protungulatum</i> Extinct genus of mammals

Protungulatum is an extinct genus of eutherian mammals within extinct family Protungulatidae, and is possibly one of the earliest known placental mammals in the fossil record, that lived in North America from the Late Cretaceous to early Paleocene.

<span class="mw-page-title-main">Afroinsectiphilia</span> Clade of mammals

The Afroinsectiphilia is a clade that has been proposed based on the results of recent molecular phylogenetic studies. Many of the taxa within it were once regarded as part of the order Insectivora, but Insectivora is now considered to be polyphyletic and obsolete. This proposed classification is based on molecular studies only, and there is no morphological evidence for it.

<span class="mw-page-title-main">Ferungulata</span> Clade of mammals comprising carnivorans, pangolins, artiodactyls and perissodactyls

Ferungulata is a grandorder of placental mammals that groups together mirorder Ferae and clade Pan-Euungulata. It has existed in two guises, a traditional one based on morphological analysis and a revised one taking into account more recent molecular analyses. The Fereungulata is a sister group to the order Chiroptera (bats) and together they make clade Scrotifera.

<span class="mw-page-title-main">Pegasoferae</span> Group of mammals comprising horses, bats, carnivores, and pangolins, among others

Pegasoferae is a proposed clade of mammals based on genomic research in molecular systematics by Nishihara, Hasegawa and Okada (2006).

<i>Cimolestes</i> Extinct genus of mammals

Cimolestes is a genus of early eutherians with a full complement of teeth adapted for eating insects and other small animals. Paleontologists have disagreed on its relationship to other mammals, in part because quite different animals were assigned to the genus, making Cimolestes a grade taxon of animals with similar features rather than a genus of closely related ones. Fossils have been found in North America, South America, Europe and Africa. Cimolestes first appeared during the Late Cretaceous of North America. According to some paleontologists, Cimolestes died out at the start of the Paleocene, while others report the genus from the early Eocene.

<span class="mw-page-title-main">Ptolemaiida</span> Extinct order of mammals

Ptolemaiida is a taxon of wolf-sized afrothere mammals that lived in northern and eastern Africa during the Paleogene. The oldest fossils are from the latest Eocene strata of the Jebel Qatrani Formation, near the Fayum oasis in Egypt. A tooth is known from an Oligocene-aged stratum in Angola, and Miocene specimens are known from Kenya and Uganda.

<span class="mw-page-title-main">Leptictida</span> Extinct order of mammals

Leptictida is a possibly paraphyletic extinct order of eutherian mammals. Their classification is contentious: according to cladistic studies, they may be (distantly) related to Euarchontoglires, although they are more recently regarded as the first branch to split from basal eutherians. One recent large-scale cladistic analysis of eutherian mammals favored lepictidans as close to the placental crown-clade; and several other recent analyses that included data from Cretaceous non-eutherian mammals found Leptictis to belong to the superorder Afrotheria.

Deccanolestes is a scansorial, basal Euarchontan from the Late Cretaceous (Maastrichtian) and Paleocene Intertrappean Beds of Andhra Pradesh, India. It may be closely related to Sahnitherium. Deccanolestes has been referred to Palaeoryctidae in the past, but recent evidence has shown that it is either the most basal Euarchontan, as the earliest known Adapisoriculid, or as a stem-afrotherian.

<span class="mw-page-title-main">Paratheria (mammals)</span> Former taxonomic group including xenarthran and similar mammals

Paratheria is an obsolete term for a taxonomic group including the xenarthran mammals and various groups thought to be related to them. It was proposed by Oldfield Thomas in 1887 to set apart the sloths, anteaters, armadillos, and pangolins, usually classified as placentals, from both marsupial and placental mammals, an arrangement that received little support from other workers. When teeth of the extinct gondwanathere mammals were first discovered in Argentina in the 1980s, they were thought to be related to xenarthrans, leading to renewed attention for the hypothesis that xenarthrans are not placentals. However, by the early 1990s, gondwanatheres were shown to be unrelated to xenarthrans, and xenarthrans are still considered to be placentals.

<span class="mw-page-title-main">Scrotifera</span> Clade of mammals

Scrotifera is a clade of placental mammals that groups together grandorder Ferungulata, Chiroptera (bats), other extinct members and their common ancestors. The clade Scrotifera is a sister group to the order Eulipotyphla based on evidence from molecular phylogenetics, and together they make superorder Laurasiatheria. The last common ancestor of Scrotifera is supposed to have diversified ca. 73.1 to 85.5 million years ago.

<span class="mw-page-title-main">Insular India</span> Isolated land mass which became the Indian subcontinent

Insular India was an isolated landmass which became the Indian subcontinent. Across the latter stages of the Cretaceous and most of the Paleocene, following the breakup of Gondwana, the Indian subcontinent remained an isolated landmass as the Indian Plate drifted across the Tethys Ocean, forming the Indian Ocean. The process of India's separation from Madagascar first began 88 million years ago, but complete isolation only occurred towards the end of the Maastrichtian, a process that has been suggested to be the creation of the Deccan Traps. Soon after, the land mass moved northward rather quickly, until contact with Asia was established 55 million years ago. Even then, both landmasses did not become fully united until around 35 million years ago, and periods of isolation occurred as recently as 24 million years ago.

Altacreodus is an extinct genus of eutherian mammals. Fossils have been found in North America where they first appeared during the Late Cretaceous, and they died out prior to the start of the Paleocene. It is possibly one of the earliest known placental mammals in the fossil record.

<span class="mw-page-title-main">Pholidotamorpha</span> Clade of mammals

Pholidotamorpha is a clade of placental mammals from mirorder Ferae that includes the order Pholidota and extinct order Palaeanodonta.

References

  1. "Cimolesta". paleobiodb.org. Retrieved 2021-08-13.
  2. 1 2 Rook, D.L.; Hunter, J.P. (2013). "Rooting Around the Eutherian Family Tree: the Origin and Relations of the Taeniodonta". Journal of Mammalian Evolution. 21: 1–17. doi:10.1007/s10914-013-9230-9. S2CID   17074668.
  3. Murphy, Willian J.; O'Brien, SJ; et al. (2001-12-14). "Resolution of the Early Placental Mammal Radiation Using Bayesian Phylogenetics". Science. 294 (5550): 2348–2351. Bibcode:2001Sci...294.2348M. doi:10.1126/science.1067179. PMID   11743200. S2CID   34367609.
  4. Beck, Robin MD; Bininda-Emonds, Olaf RP; Cardillo, Marcel; Liu, Fu-Guo; Purvis, Andy (2006). "A higher-level MRP supertree of placental mammals". BMC Evolutionary Biology. 6 (1): 93. doi: 10.1186/1471-2148-6-93 . PMC   1654192 . PMID   17101039.
  5. Cote S, Werdelin L, Seiffert ER, Barry JC (March 2007). "Additional material of the enigmatic Early Miocene mammal Kelba and its relationship to the order Ptolemaiida". Proc Natl Acad Sci USA. 104 (13): 5510–5. Bibcode:2007PNAS..104.5510C. doi: 10.1073/pnas.0700441104 . PMC   1838468 . PMID   17372202.
  6. Seiffert, Erik R (2007). "A new estimate of afrotherian phylogeny based on simultaneous analysis of genomic, morphological, and fossil evidence". BMC Evolutionary Biology. 7 (1): 224. doi: 10.1186/1471-2148-7-224 . PMC   2248600 . PMID   17999766.
  7. Clemens, W. A. (2017). Procerberus (Cimolestidae, Mammalia) from the Latest Cretaceous and Earliest Paleocene of the Northern Western Interior, USA. PaleoBios, 34, 1-26. https://escholarship.org/uc/item/1dv645n5
  8. 1 2 Eberle, J. J. (1999). Bridging the transition between didelphodonts and taeniodonts. Journal of Paleontology, 73, 936-944.
  9. Schoch, R. M. 1986. Systematics, functional morphology, and macroevolution of the extinct mammalian order Taeniodonta. Peabody Museum Bulletin, 42:1-307
  10. LILLEGRAVEN, J. A. 1969. Latest Cretaceous mammals of upper part of Edmonton Formation of Alberta, and review of marsupial-placental dichotomy in mammalian evolution. The University of Kansas Paleontological Contributions, 50(Vertebrata 12), 122.
  11. MIDDLETON, M. D. 1983. Early Paleocene vertebrates of the Denver Basin, Colorado. Unpublished Ph.D. dissertation, University of Colorado, Boulder, 404.

Sources