''Protungulatum'' ('first

ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...

') is a

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 ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of pan-euungulate

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 ...

s within extinct family Protungulatidae, and also one of the earliest known placental mammals in the fossil record, that lived in

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 th ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

to early

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pala ...

.Maeva Orliac (2016.
"The inner ear of ''Protungulatum'' (Pan-Euungulata, Mammalia)"
Journal of Mammalian Evolution 23(4) Fossils of this genus were first found in the Bug Creek Anthills in northeastern

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...

. The Bug Creek Anthills were initially believed to be Late Cretaceous (latest

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 inte ...

) because of the presence of the remains of non-avian

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s and common Cretaceous mammals, but these were later shown to have been reworked from Late Cretaceous

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...

, and consequently the Bug Creek Anthills are currently believed to be Early Paleocene ( Puercan) in age. Remains from the

Ravenscrag Formation The Ravenscrag Formation is a stratigraphic unit of early Paleocene age in the Western Canada Sedimentary Basin. It was named for the settlement of Ravenscrag, Saskatchewan, and was first described from outcrops at Ravenscrag Butte near the Fr ...

Saskatchewan Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

have been assigned to ''Protungulatum donnae''. These remains may also be Cretaceous in age, but the age of the

is not entirely certain. In

2011 File:2011 Events Collage.png, From top left, clockwise: a protester partaking in Occupy Wall Street heralds the beginning of the Occupy movement; protests against Libyan dictator Muammar Gaddafi, who was killed that October; a young man celebrates ...

, remains of a new species in this genus, ''Protungulatum coombsi'' from the

Hell Creek Formation The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of ...

(which is definitely Maastrichtian) in age, proved that ''Protungulatum'' was present in both the Cretaceous and the Paleocene. This genus was initially assigned to the order

Condylarthra Condylarthra is an informal group – previously considered an order – of extinct placental mammals, known primarily from the Paleocene and Eocene epochs. They are considered early, primitive ungulates. It is now largely considered to be a wast ...

,Malcolm C. McKenna, Susan K. Bell: ''Classification of Mammals: Above the Species Level'' in Columbia University Press, New York (1997), 631 Seiten. a group of archaic "ungulates", that is now known to be

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

. Later, it was assigned to the family

Arctocyonidae Arctocyonidae (from Greek '' arktos'' ''kyôn'', "bear/dog-like") has been defined as an extinct family of unspecialized, primitive mammals with more than 20 genera. Animals assigned to this family were most abundant during the Paleocene, but ex ...

. Studies differ on the placement of ''Protungulatum.'' Some found that it is not a true placental mammal and it is

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 ...

n found to be close to

Placentalia Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguishe ...

. Other studies consider it to be a placental mammal and stem relative to true ungulates.Averianov, A. O. & Lopatin, A. V. (2014.
"High-level systematics of placental mammals: Current status of the problem."
Biology Bulletin, 41(9), 801–816.Conference abstract (p. 99)
. Explanation and conclusions: .

Phylogeny

The phylogenetic relationships of genus ''Protungulatum'' are shown in the following cladogram.

Notes

References

{{Taxonbar, from1=Q2197682, from2=Q3924358 Prehistoric eutherians Condylarths Cretaceous mammals Paleocene mammals Hell Creek fauna Prehistoric mammals of North America Fossil taxa described in 1965 Prehistoric mammal genera