Taeniodonta ("banded teeth") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

early group of cimolestid

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s known from the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

to the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

. Taeniodonts

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...

quickly into highly specialized digging

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

s, and varied greatly in size, from rat-sized to species as large as a bear. Later species developed prominent front

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

and huge

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...

s for digging and rooting. Some genera, like ''

Stylinodon ''Stylinodon'' is an extinct genus of taeniodont mammal, and is the best known, and last genus of taeniodonts, lived some 45 million years ago during middle Eocene in North America. The skull suggests it had a blunt face, and a very short snout ...

'', had ever-growing teeth. Two

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

belong to this group, Stylinodontidae and Conoryctidae. They were

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. The scarcity of taeniodont

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s can be explained by the fact that these animals probably lived in dry or arid climates unconductive to fossilization. Taeniodonts are unambiguously

Eutheria Eutheria (; from Greek , 'good, right' and , 'beast'; ) is the clade consisting of all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from noneutherians by various phenotypic tra ...

ns, and part of

Cimolesta Cimolesta is an extinct order of non-placental eutherian mammals. 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 ...

; ''

Cimolestes ''Cimolestes'' (from Ancient Greek , 'chalk robber') 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 b ...

'' is the immediate outgroup to Taeniodonta.

Taxonomy and phylogeny

From Thomas E. Williamson and Stephen L. Brusatte (2013): * Order

:* Suborder Taeniodonta ::*'' Alveugena'' ::*''

Schowalteria ''Schowalteria'' is a genus of extinct mammal from the Cretaceous of Canada. It is the earliest known representative of Taeniodonta, a specialised lineage of non-placental eutherian mammals otherwise found in Paleocene and Eocene deposits. It is ...

'' ::* '' Onychodectes'' ::* Family Conoryctidae :::* ''

Conoryctella ''Conoryctella'' was a genus of taeniodont Taeniodonta ("banded teeth") is an extinct early group of Cimolesta, cimolestid mammals known from the Maastrichtian to the Eocene. Taeniodonts evolution, evolved quickly into highly specialized diggi ...

'' :::* '' Huerfanodon'' :::* '' Conoryctes'' ::* Family

Stylinodontidae Taeniodonta ("banded teeth") is an extinct early group of cimolestid mammals known from the Maastrichtian to the Eocene. Taeniodonts evolved quickly into highly specialized digging animals, and varied greatly in size, from rat-sized to species ...

:::* '' Chungchienia'' :::* '' Wortmania'' :::* ''

Psittacotherium ''Psittacotherium'' (meaning "parrot beast") is an extinct genus of taeniodont from the Paleocene of North America. With a weight of about and a length over , it had similar size of a large dog. References *''Mammoths, Sabertooths, and Hominids ...

'' :::* ''

Ectoganus ''Ectoganus'' is a fossil genus of mammals belonging to the family Stylinodontidae. The species of this genus are found in Northern America. Species: * ''Ectoganus bighornensis'' Schoch, 1981 * ''Ectoganus copei'' Schoch, 1981 * ''Ectoganus g ...

'' :::* ''

Notes

References

* * * Cimolestans Paleocene mammals Eocene mammals Priabonian extinctions Prehistoric mammals of North America Clawed herbivores Maastrichtian first appearances {{paleo-mammal-stub