''Adalatherium'' ( ''Adàla'', 'crazy' in Malagasy and ''therium'', 'beast' in

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

) is an extinct

gondwanatheria Gondwanatheria is an extinct group of mammaliaforms that lived in parts of Gondwana, including Madagascar, India, South America, Africa, and Antarctica during the Upper Cretaceous through the Miocene (and possibly much earlier, if '' Allostaffia' ...

n that lived in

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

during the

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

stage of the Late Cretaceous. The discovery of the first nearly-complete skeleton from the

Maevarano Formation The Maevarano Formation is a Late Cretaceous sedimentary formation (geology), rock formation found in the Mahajanga Province of northwestern Madagascar. It is most likely Maastrichtian in age, and records a seasonal, semiarid environment with rive ...

was announced in April 2020.

Description

Although the only known fossil is believed to be from a subadult individual, it had a large skull reaching long. Its body length was about and the body mass is estimated between , making it one the largest known Mesozoic mammals. It is depicted in reconstructions as being built somewhat like a badger. Its skeleton is the most complete of any Gondwanan Mesozoic mammal. Additionally, the front of the skull contains more

foramina In anatomy and osteology, a foramen (; : foramina, or foramens ; ) is an opening or enclosed gap within the dense connective tissue (bones and deep fasciae) of extant and extinct amniote animals, typically to allow passage of nerves, arter ...

than any known mammal except ''

Vincelestes ''Vincelestes'' ("Vince's thief") is an extinct genus of mammal that lived in what is now South America during the Early Cretaceous. It is closely related to modern therian mammals as part of Cladotheria. Description ''Vincelestes neuquenian ...

''.

References

Gondwanatheria Late Cretaceous mammals Maastrichtian life Cretaceous Madagascar Fossils of Madagascar Maevarano fauna Fossil taxa described in 2020 Taxa named by David W. Krause Taxa named by Simone Hoffmann Taxa named by Yaoming Hu Taxa named by John R. Wible Taxa named by Guillermo W. Rougier Taxa named by E. Christopher Kirk Taxa named by Joseph R. Groenke Taxa named by Raymond R. Rogers Taxa named by James B. Rossie Taxa named by Julia A. Schultz Taxa named by Alistair R. Evans Taxa named by Wighart von Koenigswald Taxa named by Lydia J. Rahantarisoa {{cretaceous-mammal-stub