Holoclemensia is an extinctgenusofmammal of uncertain phylogenetic placement. It lived during the Early Cretaceous and its fossil remains were discovered in Texas.
This genus is only known from a few isolated teeth. The upper molars had a paracone larger than the metacone, and a stylar platform with stylar cusps. The lower molars had a high protoconid, a small paraconid, and the hypoconulid and entoconid were close.[1]
First described in 1968 by Slaughter, Holoclemensia texana is only known from a few teeth found in the Trinity Formation, in Texas. Slaughter initially described the remains under the name Clemensia, but this name was already in use for a genus of moths and the genus was renamed Holoclemensia. It was initially considered to be a basal marsupial, then was approached of the so-called group "Tribotheria",[2] was later reconsidered as a marsupial,[3] and was finally placed as a basal member of Metatheria.[4] Despite its uncertain classification, Holoclemensia was probably close to the point where Metatherians and Eutherians diverged from each other.
^Slaughter, B. H. 1971. Mid-Cretaceous (Albian) therians of the Butler Farm local fauna, Texas. Zoological Journal of the Linnean Society 50:131–143.
^Butler, P. M. 1978. A new interpretation of the mammalian teeth of tribosphenic pattern from the Albian of Texas. Breviora 446:1–27.
^Cifelli, R. L. 1993. Theria of metatherian-eutherian grade and the origin of marsupials; pp. 205–215 in F. S. Szalay, M. J. Novacek, and M. C. McKenna (eds.), Mammal Phylogeny: Mesozoic Differentiation, Multituberculates, Monotremes, Early Therians, and Marsupials. Springer-Verlag, New York.
^*Luo, Z.-X., Q. Ji, J. R. Wible, and C.-X. Yuan. 2003. An Early Cretaceous tribosphenic mammal and metatherian evolution. Science 302:1934–1940.
Slaughter, B. H. 1968. Earliest known marsupials. Science 162:254-255
Slaughter, B. H. 1968. Holoclemensia instead of Clemensia. Science 162:1306
Davis, B.M. and Cifelli, R.L. 2011. Reappraisal of the tribosphenidan mammals from the Trinity Group (Aptian–Albian) of Texas and Oklahoma. Acta Palaeontologica Polonica 56 (3): 441–462.
