''Borealosuchus'' (meaning "
boreal
Boreal may refer to:
Climatology and geography
*Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch
*Boreal climate, a climate characterized by long winters and short, cool to mild ...
crocodile") 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 ...
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
crocodyliform
Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseudo ...
s that lived 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'', the ...
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' ...
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 the Car ...
. It was named by Chris Brochu in 1997 for several
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
that had been assigned to ''
Leidyosuchus
''Leidyosuchus'' (meaning " Leidy's crocodile") is an extinct genus of alligatoroid from the Late Cretaceous of Alberta. It was named in 1907 by Lawrence Lambe, and the type species is ''L. canadensis''. It is known from a number of specimens fro ...
''. The species assigned to it are: ''B. sternbergii'', the
type species
In 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 species that contains the biological type specimen ...
, 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 ...
(Late Cretaceous) of
Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...
,
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 Columbi ...
,
North Dakota
North Dakota () is a U.S. state in the Upper Midwest, named after the Native Americans in the United States, indigenous Dakota people, Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north a ...
,
South Dakota
South Dakota (; Sioux language, Sioux: , ) is a U.S. 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 Lakota people, Lakota and Dakota peo ...
, and
Wyoming
Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...
; ''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), E ...
of
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 ...
; ''B. formidabilis'', from the Paleocene of North Dakota;
''B. griffithi'', from the Paleocene of
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
;
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 The Wannagan Creek site is a fossil site found just west of the South Unit of Theodore Roosevelt National Park of North Dakota, USA. The site is Paleocene in age, approximately 60 million years old. Paleontologists of the Science Museum of Minnesot ...
in North Dakota.
''Borealosuchus'' was a mid-sized crocodyliform; ''B. acutidentatus'' reached up to in length with a skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...
.
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 located in the U.S. state of New Jersey. As of the 2020 U.S. census, the county's population was 302,294.
Gloucester County is located approximately southeast of Philadelphia and northwest of Atlantic City. I ...
. 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 highways in the U.S. state of New Jersey. The turnpike is maintained by the New Jersey Turnpike Authority (NJTA).The Garden State Parkway, although maintained by NJTA, is not consi ...
, 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?'".
Classification
Although some earlier phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
studies proposed ''Borealosuchus'' to be a member of Crocodylia
Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period (Cenomanian stage) and are the closest living ...
, recent studies are now recovering ''Borealosuchus'' as a basal eusuchia
Eusuchia is a clade of crocodylomorphs that first appeared in the Early Cretaceous with ''Hylaeochampsa''. Along with Dyrosauridae and Sebecosuchia, they were the only crocodyliformes who survived the K-T extinction. Since the other two clades d ...
n not belonging to Crocodylia, as shown in the cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
below:
References
External links
''Borealosuchus''
in the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms.
History
The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ...
{{Taxonbar, from=Q2489118, from2=Q12899046, from3=Q12899047, from4=Q12899045, from5=Q21256030, from6=Q12899041
Neosuchians
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