''Tinodon'' is an extinct genus of mammal alive 155–140.2 million years ago ( Oxfordian-

Berriasian In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago) ...

) which has been found in the

Morrison Formation The Morrison Formation is a distinctive sequence of Late Jurassic, Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandsto ...

(

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

),Foster, J. (2007). "Appendix." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. ''Indiana University Press.'' pp. 327-329. the

Alcobaça Formation The Alcobaça Formation, previously known as the Guimarota Formation and also known as the Consolação Unit, is a geological formation in Portugal. It dates back to the Kimmeridgian stage of the Late Jurassic. It is an important source of informa ...

(

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

) and the

Lulworth Formation The Lulworth Formation is a Formation (geology), geologic formation in England. It dates from the late Tithonian to the mid Berriasian. It is a subunit of the Purbeck Group. In Dorset, it consists of three members, which are in ascending order, t ...

(

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

). It is of uncertain affinities, being most recently recovered as closer to

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. Ch ...

ns than

eutriconodont Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia, Africa, Europe, North and South America during the Jurassic and the Cretaceous periods. The order was named by Kermack ''et al.'' in 1973 as a replacement name for the ...

s but less so than

allotheria Allotheria (meaning "other beasts", from the Greek , '–other and , '–wild animal) is an extinct branch of successful Mesozoic mammals. The most important characteristic was the presence of lower molariform teeth equipped with two longitudin ...

ns.S. Bi, Y. Wang, J. Guan, Z. Sheng, and J. Meng. 2014. Three new Jurassic euharamiyidan species reinforce early divergence of mammals. ''Nature'' 514:579-584 . Mannion/J. Tennant/ref> Two species are known: ''T. bellus'' (Marsh, 1879) and ''T. micron'' (Ensom & Sigogneau-Russell, 2000P. Ensom and D. Sigogneau-Russell. 2000. New symmetrodonts (Mammalia, Theria) from the Purbeck Limestone Group, Lower Cretaceous, southern England. ''Cretaceous Research'' 21:767-779).

References

Morrison mammals Taxa named by Othniel Charles Marsh Fossil taxa described in 1879 Prehistoric mammal genera {{jurassic-mammal-stub

See also

References