The Litopterna, like the notoungulates and pyrotheres, are examples of ungulate mammals that arose relatively independently in "splendid isolation" on the island continent of South America. Like Australia, South America was isolated from all other continents following the breakup of Gondwana. During this period of isolation, unique mammals evolved to fill ecological niches similar to other mammals elsewhere. The Litopterna occupied ecological roles as browsers and grazers similar to horses and camels in Laurasia.
Astrapotheria is an extinct order of South American and Antarctic hoofed mammals that existed from the Late Paleocene to the Middle Miocene,. Astrapotheres were large and rhinoceros-like animals and have been called one of the most bizarre orders of mammals with an enigmatic evolutionary history. This taxonomy of this order is not clear, but it may belong to Meridiungulata (along with Notoungulata, Litopterna, Pyrotheria and Xenungulata). In turn, Meridungulata is believed to belong to the extant superorder Laurasiatheria. Some scientists have regarded the astrapotheres (and sometimes the Meridiungulata all together) as members of the clade Atlantogenata.
How dinoceratans are related to other mammals is in dispute. They are probably part of the hoofed mammal (ungulate) group and have similarities with some South American hoofed mammals, namely, the primitive Carodnia of Paleocene South America. Another idea is that dinoceratans are closely related to pantodonts and tillodonts. A more controversial view is that dinoceratans descend from the anagalids, a small group of rabbit-like mammals. But they may be related to an ungulatomorph group called zhelestidae.
Eparctyona is a clade of placental mammals comprising the artiodactyls (even-toed ungulates), cetacea (whales and related), and the extinct condylarths.
"A sub-complete fossil aardvark (Mammalia, Tubulidentata) from the Upper Miocene of Chad". MacInnes D. G. (1956). Fossil Tubulidentata from East Africa. British Museum (Natural History), London. Fossil mammals of Africa series; no. 10. 46 pp.
In medieval China, the fossil bones of ancient mammals including Homo erectus were often mistaken for "dragon bones" and used as medicine and aphrodisiacs. In addition, some of these fossil bones are collected as "art" by scholars, who left scripts on various artifacts, indicating the time they were added to a collection. One good example is the famous scholar Huang Tingjian of the South Song Dynasty during the 11th century, who kept a specific seashell fossil with his own poem engraved on it. In the West fossilized sea creatures on mountainsides were seen as proof of the biblical deluge.
aardvarksOrycteropus aferant bear
Along with the sirenians, hyraxes, elephants, and their extinct relatives, these animals form the superorder Afrotheria. Studies of the brain have shown the similarities with Condylarthra, and given the clade's status as a wastebasket taxon it may mean some species traditionally classified as "condylarths" are actually stem-aardvarks. Based on fossils, Bryan Patterson has concluded that early relatives of the aardvark appeared in Africa around the end of the Paleocene. The ptolemaiidans, a mysterious clade of mammals with uncertain affinities, may actually be stem-aardvarks, either as a sister clade to Tubulidentata or as a grade leading to true tubulidentates.
In biology, taxonomy is the science of naming, defining (circumscribing) and classifying groups of biological organisms on the basis of shared characteristics. Organisms are grouped together into taxa (singular: taxon) and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a super-group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum (division is sometimes used in botany in place of phylum), class, order, family, genus, and species.
A 2018 study indicated that the sixth mass extinction started in the Late Pleistocene could take up to 5 to 7 million years to restore 2.5 billion years of unique mammal diversity to what it was before the human era. Extinction of a parent species where daughter species or subspecies are still extant is called pseudoextinction or phyletic extinction. Effectively, the old taxon vanishes, transformed (anagenesis) into a successor, or split into more than one (cladogenesis). Pseudoextinction is difficult to demonstrate unless one has a strong chain of evidence linking a living species to members of a pre-existing species.
LinnaeusL.Carl von Linné
It was also during this expedition that Linnaeus had a flash of insight regarding the classification of mammals. Upon observing the lower jawbone of a horse at the side of a road he was travelling, Linnaeus remarked: "If I only knew how many teeth and of what kind every animal had, how many teats and where they were placed, I should perhaps be able to work out a perfectly natural system for the arrangement of all quadrupeds." In 1734, Linnaeus led a small group of students to Dalarna. Funded by the Governor of Dalarna, the expedition was to catalogue known natural resources and discover new ones, but also to gather intelligence on Norwegian mining activities at Røros.
Both mammals and birds are able to maintain a high constant body temperature (i.e., they are warm-blooded). However, the accepted cladogram explaining their significant features indicates that their common ancestor is in a group lacking this character state, so the state must have evolved independently in the two clades. Warm-bloodedness is separately a synapomorphy of mammals (or a larger clade) and of birds (or a larger clade), but it is not a synapomorphy of any group including both these clades.
In cladistics, a monophyletic group, or clade, is a group of organisms that consists of all the descendants of a common ancestor (or more precisely ancestral population). Monophyletic groups are typically characterised by shared derived characteristics (synapomorphies), which distinguish organisms in the clade from other organisms. The arrangement of the members of a monophyletic group is called a monophyly.
Class Synapsida (mammals; 5,700+ species). Chordate genomics. List of chordate orders. Chordate on GlobalTwitcher.com. Chordate node at Tree Of Life. Chordate node at NCBI Taxonomy.
Updated analysis of transposable element insertions around the time of divergence strongly supports the fourth hypothesis of a near-concomitant origin (trifurcation) of the three superorders of mammals: Afrotheria, Boreoeutheria, and Xenarthra. Below shows the phylogeny of the extant atlantogenate families. *
lionsAfrican lionPanthera leo
Its prey consists mainly of mammals – particularly ungulates – weighing 190–550 kg with a preference for blue wildebeest, plains zebra, African buffalo, gemsbok and giraffe. Lions also hunt common warthog depending on availability, although the species is below the preferred weight range. In India, sambar deer and chital are the most commonly recorded wild prey, while domestic livestock may contribute significantly to their diet. They usually avoid fully grown adult elephants, rhinoceroses and hippopotamus, as well as small prey like dik-dik, hyrax, hare and vervet monkey. Unusual prey items include porcupines and small reptiles.
Arctostylopida is an extinct order of placental mammals from the Late Palaeocene of Eastern Asia and North America. All arctostylopid specimens in North America have been referred to the genus Arctostylops. They are animals of uncertain affinities to other groups and it was believed that they may be related to 'ungulates'. Originally they were considered to be northern relatives of South American notoungulates, specifically Notostylopidae. Recently, other palaeontologists have suggested that they might be descendants of Asian gliriforms, and therefore related to rabbits and rodents. This relationship is based upon similarities in the shape of their tarsal (ankle) bones.
The family has also thought to be ancestral to the Sirenia. They superficially resemble the Moeritheriidae in both size and cheek tooth morphology, but lack their characteristic tusks. They were relatively small, ranging in size from 1 to 2 m in length. They are known only from fragmentary remains (mainly teeth) from Eocene deposits of the northwestern part of the Indo-Pakistan subcontinent. Recently excavated fossils with well-preserved jaws and teeth demonstrate that these animals were actually perissodactyls. The anthracobunids were probably amphibious and lived in marshy environments.
MoeritheriidaeMoeritherium andrewsi?Moeritherium sp.
These prehistoric mammals are related to the elephant and, more distantly, sea cows and hyraxes. They lived during the Eocene epoch. Moeritherium was a rotund semi-aquatic mammal with short, stubby legs that lived about 37-35 million years ago Its body shape and lifestyle demonstrate convergent evolution with pigs, tapirs, and the pygmy hippopotamus. Moeritherium was smaller than most or all later proboscideans, standing only 70 cm high at the shoulder and weighing 235 kg. The shape of their teeth suggests that they ate soft water vegetation.
. * * Paleocene-Mammals
A study on the response of large ungulates to the palaeoenvironmental changes that occurred at the passage between the Gelasian and Calabrian in the Italian Peninsula, based on the dental wear patterns and hypsodonty of the ungulates from the fossil assemblage of Olivola (Aulla, Italy), is published by Strani et al. (2018). A study on the ungulate and carnivoran carrying capacity of the late Early and early Middle Pleistocene ecosystems of Europe is published by Rodríguez & Mateos (2018).
This article records new taxa of fossil mammals of every kind that have been described during the year 2016, as well as other significant discoveries and events related to paleontology of mammals that occurred in the year 2016. A near-complete skull, a snout and two maxillae assigned to the species Didelphodon vorax are described from the Late Cretaceous Hell Creek Formation (Montana and North Dakota, United States) by Wilson et al. (2016). Description of a new specimen of Malleodectes mirabilis and a study of phylogenetic relationships of this species is published by Archer et al. (2016).
manatee evolutionof sirenians
Sirenians, along with Proboscidea (elephants), group together with the extinct Desmostylia and likely the extinct Embrithopoda to form the Tethytheria. Tethytheria is thought to have evolved from primitive hoofed mammals ("condylarths") along the shores of the ancient Tethys Ocean. Tethytheria, combined with Hyracoidea (hyraxes), forms a clade called Paenungulata. Paenungulata and Tethytheria (especially the latter) are among the least controversial mammalian clades, with strong support from morphological and molecular interpretations. The ancestry of Sirenia is remote from that of Cetacea and Pinnipedia, although they are thought to have evolved an aquatic lifestyle around the same time.
Pseudoungulata, or "false hoofed mammals", is a possible clade made up of two subgroups, aardvarks and paenungulates (hyraxes, elephants, and sirenians). Before this group was proposed, it was thought that aardvarks were more closely related to xenarthrans. However, all of these mammals are now considered to be part of Afrotheria, which also includes elephant shrews and afrosoricidans. Other positions of aardvarks within Afrotheria are possible, such as being closest relatives of elephant shrews and/or afrosoricidans.
LebanonMammals of Lebanon
Lists of mammals by region. List of prehistoric mammals. Mammal classification. List of mammals described in the 2000s. Wildlife of Lebanon.