''Borealosuchus'' (meaning "northern crocodile") is an
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
crocodyliforms that lived from the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...
to the
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
in
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
. It was named by Christopher Brochu in 1997 for several
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
that had been assigned to ''
Leidyosuchus''. The species assigned to it are: ''B. sternbergii'', the
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
, from 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 ...
(Late Cretaceous) of
Colorado
Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
,
Montana
Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...
,
North Dakota
North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...
,
South Dakota
South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...
, and
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...
; ''B. acutidentatus'', from the
Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
of
Saskatchewan
Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...
; ''B. formidabilis'', from the Paleocene of North Dakota;
''B. griffithi'', from the Paleocene of
Alberta
Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...
;
and ''B. wilsoni'', from the Eocene of Wyoming.
[ ''B. formidabilis'' is particularly well-known, represented by the remains of many individuals from the Wannagan Creek site in North Dakota.] An indeterminate species is known from the Late Cretaceous Demopolis Chalk in Alabama
Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...
.
''Borealosuchus'' was a mid-sized crocodyliform, with ''B. wilsoni'' measuring approximately long.
Taxonomy
Six species of ''Borealosuchus'' are currently recognized. In order of their naming, they are ''B. sternbergii'', ''B. acutidentatus'', ''B. wilsoni'', ''B. formidabilis'', ''B. griffithi'', and ''B. threeensis''.
Fossilworks Four of these species (''B. sternbergi'', ''B. acutidentatus'', ''B. wilsoni'', and ''B. formidabilis'') were originally named as species of ''Leidyosuchus''. A sixth species of ''Borealosuchus'', ''B. threeensis'', was named in 2012. Fossils of this species were found in the Inversand Company Marl Pit of Gloucester County, New Jersey
Gloucester County ( ) is a County (United States), county in the U.S. state of New Jersey. As of the 2020 United States census, 2020 census, the county was the state's List of counties in New Jersey, 14th-most populous county . The specific name is a reference to Exit 3 of the New Jersey Turnpike
The New Jersey Turnpike (NJTP) is a system of controlled-access highway, controlled-access toll roads in the U.S. state of New Jersey. The turnpike is maintained by the New Jersey Turnpike Authority (NJTA).The Garden State Parkway, although ma ...
, which is the closest highway exit to the type locality. The authors of the paper describing ''B. threeensis'' noted that the name is "in reference to a question every New Jersey resident encounters when traveling: 'Oh, you're from New Jersey? Which exit?'".
*†''B. sternbergii''
**Moved from ''Leidyosuchus sternbergii''
*†''B. acutidentatus''
**Moved from ''L. acutidentatus''
*†''B. formidabilis''
**Moved from ''L. formidabilis''
*†''B. griffithi''
*†''B. threeensis''
*†''B. wilsoni''
**Moved from ''L. wilsoni''
Classification
Although some earlier phylogenetic
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
studies proposed ''Borealosuchus'' to be a member of Crocodylia
Crocodilia () is an Order (biology), order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorp ...
, recent studies are now recovering ''Borealosuchus'' as a basal eusuchia
Eusuchia is a clade of neosuchian Crocodylomorpha, crocodylomorphs that first appeared in the Early Cretaceous, which includes modern Crocodilia, crocodilians. Along with Dyrosauridae and Sebecosuchia, they were the only crocodyliformes who survi ...
n not belonging to Crocodylia, as shown in the cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
below:
References
External links
''Borealosuchus''
in the Paleobiology Database
The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms.
History
The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...
{{Taxonbar, from=Q2489118, from2=Q12899046, from3=Q12899047, from4=Q12899045, from5=Q21256030, from6=Q12899041
Neosuchia
Paleocene crocodylomorphs
Eocene crocodylomorphs
Late Cretaceous crocodylomorphs of North America
Late Cretaceous reptiles of North America
Hell Creek fauna
Paleocene reptiles of North America
Eocene reptiles of North America
Fossil taxa described in 1997
Prehistoric pseudosuchian genera
Paleontology in Alberta