Theria

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Theria

One of the four subclasses of the class Mammalia, including all living mammals except the monotremes. The Theria were by far the most successful of the several mammalian stocks that arose from the mammallike reptiles in the Triassic. The subclass is divided into three infraclasses: Pantotheria (no living survivors), Metatheria (marsupials), and Eutheria (placentals). Therian mammals are characterized by the distinctive structural history of the molar teeth. The fossil record shows that all the extremely varied therian molar types were derived from a common tribosphenic type in which three main cusps, arranged in a triangle on the upper molar, are opposed to a reversed triangle and basinlike heel on the lower molar. See Mammalia

Theria

[′ther·ē·ə]
(vertebrate zoology)
A subclass of the class Mammalia including all living mammals except the monotremes.
References in periodicals archive ?
We demonstrated that PEG10 is specific to the therian mammals, (16) while Ferguson-Smith's group demonstrated that PEG11/RTL1 is a eutherian-specific gene that is absent from marsupials.
Origin of the Tooth-Replacement Pattern in Therian Mammals: Evidence from a 110 Myr Old Fossil.
Of the 378 event pairs discussed here, 57% are uniform (or uniform with a single exception) in the nine therian taxa examined; 81% are uniform (or have a single exception) among the four metatherians, and 77% are uniform (or with a single exception) in the five eutherians.
Other reptilian and therian groups were also well represented, in particular those that made up the microfauna.
Petrosals of Late Cretaceous Marsupials from North America, and a Cladistic Analysis of the Petrosal in Therian Mammals.
No amphi-Atlantic genotypes were detected; Ber mudan lineages co-clustered exclusively with Floridian congeners to form a western Atlantic dade and Azorean samples formed an exclusive dade with Therian haplotypes.
1990a) noted that the Trinity frogs, lizards, and therian mammals also are characterized by a complex mosaic of primitive and derived characters and speculated that this may reflect conditions during the adaptive radiation undergone by these groups during Trinity times.
299, Ken Jones 279, Therian Stone 279, Derrick White 279, Scott Fenn 278.
HIGH SERIES - Open: Charlie Keller 729, Coleman 722, Therian Stone 716, Richard Goosmann 709, Larry Dillon 708.
Didelphids constitute a basal group of marsupials consisting of relatively generalized forms thought to provide a model or at least appropriate comparison in studies of basal therian evolution (Szalay, 1994).
Evolution of the mammalian mitochondrial control region--comparisons of control region sequences between monotreme and therian mammals.