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Coloniatherium
''Coloniatherium'' is a meridiolestid mammal from the Late Cretaceous of Argentina. The single species, ''Coloniatherium cilinskii'', was a large member of the family Mesungulatidae. Taxonomy ''Coloniatherium'' was named in 2009 by Guillermo Rougier and colleagues and assigned to the family Mesungulatidae within the Dryolestoidea. Dryolestoidea is an extinct mammalian group that occurred in North America, Eurasia, and Africa during the Jurassic and Early Cretaceous, but survived in South America during the Late Cretaceous and into the Paleocene. The generic name, ''Coloniatherium'', combines the name of the La Colonia Formation, the stratigraphical unit where fossils of the animal were found, and its namesake the Sierra de La Colonia with the Greek ''therion'' "beast". The specific name, ''cilinskii'', honors Juan Cilinski, a local rancher who helped with the fieldwork that led to the discovery of ''Coloniatherium''. Description ''Coloniatherium'' is known from a few j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferugliotherium
''Ferugliotherium'' is a genus of fossil mammals in the family Ferugliotheriidae from the Campanian and/or Maastrichtian period (Late Cretaceous; around 70 million years ago) of Argentina. It contains a single species, ''Ferugliotherium windhauseni'', which was first described in 1986. Although originally interpreted on the basis of a single brachydont (low- crowned) molar as a member of Multituberculata, an extinct group of small, rodent-like mammals, it was recognized as related to the hypsodont (high-crowned) Sudamericidae following the discovery of additional material in the early 1990s. After a jaw of the sudamericid ''Sudamerica'' was described in 1999, these animals (collectively known as Gondwanatheria) were no longer considered to be multituberculates and a few fossils that were previously considered to be ''Ferugliotherium'' were assigned to unspecified multituberculates instead. Since 2005, a relationship between gondwanatheres and multituberculates has again received s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Colonia Formation
The La Colonia Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., 2004, pp.600-604 Originally thought to be Campanian (c.73-72 million years ago) in age or earlier, studies of underlying formations have made a Maastrichtian (70–66 million years ago) age more likely.Rauhut, 2003 It is divided up into three distinct facies, the first is up to thick and consists of conglomerate, the second is by far the thickest at over , consists of siltstone and claystone, with interbeds of claystone/shale and sandstone, the third is less than thick and consists of clay, and probably represents a nearshore marine environment.Gasparini et al., 2015 Flora The paleoflora was known for its aquatic components, ''Paleoazolla'' and ''Regnellidium''. However, recent paleobotanical discoveries at the Cañadón del Irupé locality have revealed the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meridiolestid
Meridiolestida is an extinct clade of mammals known from the Cretaceous and Cenozoic of South America and possibly Antarctica. They represented the dominant group of mammals in South America during the Late Cretaceous. Meridiolestidans were morphologically diverse, containing both small insectivores such as the "sabretooth-squirrel" '' Cronopio,supplementary information '' as well as the clade Mesungulatoidea/Mesungulatomorpha, which ranged in size from the shrew-sized '''' to the dog-sized '' |
Mesungulatidae
Mesungulatidae is an extinct clade of meridiolestidan dryolestoid mammals from the Late Cretaceous of South America and possibly other Gondwannan landmasses. They are particularly notable for their ecological speciation and large size. Characteristics Most mesungulatids are generally large animals, making them inherently distinctive from other groups. Specific synapomorphies include a strong precingulum and postcingulum on the upper molars - which are extended lingually but do not meet around the paracone - three cusps on the lower stylar shelf, an absent metacone and rectangular lower molars. They are thought to have had a somewhat transverse mastication, like docodonts and modern ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...s. Compared to other dryolestoids thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dryolestoidea
Dryolestida is an extinct order of mammals, primarily and possibly exclusively known from the Jurassic and Cretaceous. They are considered members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they developed a fully mammalian jaw and also had the three middle ear bones. Most members of the group, as with most Mesozoic mammals, are only known from fragmentary tooth and jaw remains. The taxonomic composition of the group is contested. Aside from the uncontroversial Dryolestidae and the possibly paraphyletic Paurodontidae, which were small insectivores, known from the Middle Jurassic to Early Cretaceous of Laurasia, the Meridiolestida, a diverse group of mammals including both small insectivores and mid-large sized herbivores known from the Late Cretaceous to Miocene of South America and possibly Antarctica, are also often included. However, in many phylogenetic analyses, Meridiolestida are recovered as an unrelated group of cladotheri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vincelestes
''Vincelestes'' ("Vince's thief") is an extinct genus of actively mobile mammal, that lived in what would be South America during the Early Cretaceous from 130 to 112 mya, existing for approximately . Description ''Vincelestes neuquenianus'' is the only species known to date. Specimens were found in La Amarga Formation of southern Neuquén Province, Argentina. The remains of only nine individuals were recovered from this site. The back teeth of ''Vincelestes'' were similar to those of therians in that they were capable of cutting and grinding. This enabled them to process food more efficiently. Diet In one study on Mesozoic mammal mandibles, ''Vincelestes'' plots with herbivorous and omnivorous taxa. Phylogeny Although not the direct ancestor of therians, ''Vincelestes'' is important because it gives an idea of what the ancestor of both placental and marsupial mammals might have looked like, and also gives an indication of when these mammals may have originated. Some stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theria
Theria (; Greek: , wild beast) is a subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the placental mammals) and the metatherians (including the marsupials) but excludes the egg-laying monotremes. Characteristics Therian mammals give birth (''see viviparity'') to live young without a shelled egg. This is possible thanks to key proteins called syncytins which allow exchanges between the mother and its offspring through a placenta, even rudimental ones such as in marsupials. Genetic studies have suggested a viral origin of syncytins through the endogenization process. The marsupials and the placental mammals evolved from a common therian ancestor that gave live birth by suppressing the mother's immune system. While the marsupials continued to give birth to an underdeveloped fetus after a short pregnancy, the ancestors of placental mammals gradually evolved a prolonged pregnancy. Therian mammals no longer have the coracoid bone, con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chubut Province
Chubut ( es, Provincia del Chubut, ; cy, Talaith Chubut) is a province in southern Argentina, situated between the 42nd parallel south (the border with Río Negro Province), the 46th parallel south (bordering Santa Cruz Province), the Andes range to the west, and the Atlantic ocean to the east. The province's name derives from the Tehuelche word , meaning "transparent," their description of the Chubut River. The largest city is Comodoro Rivadavia in the south of the province; it has 180,000 inhabitants. The administrative capital is Rawson (40,000). Other important cities are Puerto Madryn, Trelew, Esquel and Sarmiento. Gaiman is a cultural and demographic centre of the region known as ''"Y Wladfa"'' in which Welsh-Argentines are concentrated. Of the 25,000 Welsh speakers in Argentina, 5,000 live in the Chubut region, particularly in the early Welsh settlements of Gaiman, Trelew and Trevelin. History Before the Spaniards arrived in the Americas, nomadic indigenous Tehu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in North America, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...ia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus (biology), 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 (marsupial), pouch. Anatomical features Placental mammals are anatomically distinguished from othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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