''Boreopricea'' 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 ...

archosauromorph Archosauromorpha (Greek for "ruling lizard forms") is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs (such as crocodilians and dinosaurs, including birds) rather than lepidosaurs (such as tuataras, liza ...

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

from the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. It is known from a fairly complete skeleton discovered in a borehole on

Kolguyev Island Kolguyev Island (russian: о́стров Колгу́ев) is an island in Nenets Autonomous Okrug of Russia, located in the south-eastern Barents Sea (west of the Pechora Sea) to the north-east of the Kanin Peninsula. Origin of the name There ...

, though damage to the specimen and loss of certain bones has complicated study of the genus. ''Boreopricea'' shared many similarities with various other archosauromorphs, making its classification controversial. Various studies have considered it a close relative of ''

Prolacerta ''Prolacerta'' is a genus of archosauromorph from the lower Triassic of South Africa and Antarctica. The only known species is ''Prolacerta broomi''. The generic name ''Prolacerta'' is derived from Latin meaning “before lizard” and its speci ...

'', tanystropheids, both, or neither. ''Boreopricea'' is unique among early archosauromorphs due to possessing contact between the

jugal The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy ...

and

squamosal The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal The quadratojugal is a skull bone present in many vertebrates, including ...

bones at the rear half of the skull.

History

''Boreopricea funerea'' was named and described by

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

paleontologist L. P. Tatarinov in 1978. It was primarily based on a fairly complete skull and skeleton collected in 1972 from a

borehole A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petro ...

in the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

. This

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen,

PIN A pin is a device used for fastening objects or material together. Pin or PIN may also refer to: Computers and technology * Personal identification number (PIN), to access a secured system ** PIN pad, a PIN entry device * PIN, a former Dutch ...

3708/1, included bones from most of the body, apart from the hip area, the tip of the snout, and various miscellaneous missing fragments. During Tatarinov's preparation, the bones were removed from a slab of rock and glued onto a large piece of

card stock Card stock, also called cover stock and pasteboard, is paper that is thicker and more durable than normal writing and printing paper, but thinner and more flexible than other forms of paperboard. Card stock is often used for business cards, ...

, positioned as they originally were in the rock. Tatarinov also mentioned a second specimen, PIN 3708/2, which was a portion of the snout. However, this specimen could not be found by subsequent studies and is now considered lost. The rock layers preserving ''Boreopricea'' fossils hail from the

Ustmylian Gorizont The Ustmylian Gorizont (geology), Gorizont ("Ustmylian Horizon") is a Lower Triassic biostratigraphic unit in Western Russia. The Ustmylian Gorizont is the youngest subunit of the Vetlugian Supergorizont, lying above the Sludkian Gorizont and below ...

, the most recent portion of the Vetlugian Supergorizont. The Ustmylian Gorizont is a regional biochronological zone which corresponds to the early

Olenekian In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between Ma and Ma (million years ago). The Olenekian is sometimes divided into ...

stage of the

. The genus was redescribed in 1997 by

University of Bristol , mottoeng = earningpromotes one's innate power (from Horace, ''Ode 4.4'') , established = 1595 – Merchant Venturers School1876 – University College, Bristol1909 – received royal charter , type ...

paleontologists

Michael Benton Michael James Benton One or more of the preceding sentences incorporates text from the royalsociety.org website where: (born 8 April 1956) is a British palaeontologist, and professor of vertebrate palaeontology in the School of Earth Sciences ...

and Jackie Allen. They found that the specimen had been damaged during storage, as the skull was crushed and certain bones were missing (i.e. parts of the shoulder) or placed into odd positions (i.e. the hand). A plaster cast of the skull prior to its crushing was utilized for their description of the skull, but some areas, such as the

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sepa ...

and braincase, eluded restudy. Further study of the specimen was undertaken as part of

Martin Ezcurra Martin may refer to: Places * Martin City (disambiguation) * Martin County (disambiguation) * Martin Township (disambiguation) Antarctica * Martin Peninsula, Marie Byrd Land * Port Martin, Adelie Land * Point Martin, South Orkney Islands Austral ...

's 2016 study on archosauromorph systematics.

Description

''Boreopricea'' would have had a sprawling posture and a generalized lizard-like body shape, though with a longer neck than most modern lizards. Benton & Allen (1997) estimated that ''Boreopricea'' had a total (snout tip to tail tip) length of 44.0 centimeters (17.3 inches), with a 2.9 cm (1.1 inch) skull and 23.0 cm (9.1 inch) inch tail, although these estimates are uncertain considering that the tip of the snout and large portions of the backbone are missing.

Skull

The skull had a broad snout, large

orbits In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...

(eye sockets), and two temporal fenestrae (holes at the back of the skull) like other

diapsid Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The group first appeared about three hundred million years ago ...

reptiles. Bones which lie at the top edge of the head, such as the nasal and

frontal bones The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...

, were rectangular. The

parietal bones The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named ...

are incomplete, but preserved portions contact the frontals along a straight edge without a parietal foramen (a hole in the skull, present in many reptiles, which houses the

pineal gland The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep, sleep patterns in both circadian rhythm, circ ...

). The

(cheek bone) was unusually shaped. It lacked a posterior process (lower rear prong), which meant that the lower temporal fenestra was open from below. Conversely, the ascending process (upper rear prong) was elongated, stretching above the lower temporal fenestra to contact the

squamosal bone The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...

at the rear of the skull. This jugal-squamosal contact (unique to ''Boreopricea'' among early archosauromorphs) effectively barricades the

postorbital bone The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some ve ...

from the edge of the lower temporal fenestra. The lower jaw was long and slender. Teeth, when preserved, were conical, sharply pointed, and slightly curved.

Postcranial skeleton

The neck was somewhat elongated. A sequence of five cervical (neck) vertebrae were preserved, probably the third to seventh vertebrae in the backbone. They were longer and narrower towards the skull and shorter and wider towards the shoulder. The later cervical and dorsal (torso) vertebrae had two rib facets on each side: a large, outwards-projecting facet which was triangular in cross section, and a smaller, circular facet which barely projects at all. The upwards-projecting neural spines of the vertebrae were low. Cervicals had narrow neural spines while dorsals had neural spines which gradually expanded into teardrop-shaped structures when seen from above. These expansions on the neural spines have been termed mammillary processes. The caudal (tail) vertebrae were numerous; they were broader towards the base of the tail and much thinner towards the tip. The

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

(shoulder blade) was very thin when seen head-on but large and boxy when seen from the side. Other shoulder bones, including a bony sternum, were described by Tatarinov (1978) but are now lost. The

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

(upper arm bone) had a shape like a heavily twisted hourglass, with the long axis of the portion near the shoulder offset at a right angle from that of the portion near the elbow. The

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

and

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

(lower arm bones) were thin, curved rods like those of most other reptiles. Metacarpal III (the third bone of the hand) was as long as if not longer than metacarpal IV (the fourth bone of the hand), as with tanystropheids. Hindlimb bones are overall fairly typical in structure, although the

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

(thigh bone) was broader than in most reptiles. The ankle was formed by four tightly-connected bones: the centrale,

astragalus ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to tempe ...

calcaneum In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock. St ...

, and distal tarsal IV. Although the astragalus and calcaneum were the most prominent bones in the ankle, all of the ankle bones were similar in size. ''Boreopricea'' also lacked a hole along the contact between the astragalus and calcaneum and the second

phalanx The phalanx ( grc, φάλαγξ; plural phalanxes or phalanges, , ) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar pole weapons. The term is particularly use ...

(toe bone) of the fifth toe was long, both traits shared by tanystropheids. Metatarsal V (the fifth bone of the foot) was hook-shaped, as with various other archosauromorphs.

Classification

When first described in 1978, ''Boreopricea'' was considered to be a "prolacertiform" reptile, meaning that its closest relatives were believed to be other long-necked lizard-like creatures such as ''

'' and ''

Macrocnemus ''Macrocnemus'' is an extinct genus of archosauromorph reptile known from the Middle Triassic (Late Anisian to Ladinian) of Europe and China. ''Macrocnemus'' is a member of the Tanystropheidae family and includes three species''. Macrocnemus bass ...

''. At this time, it was uncertain whether "prolacertiforms" were truly ancestral to modern

lizards Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia althou ...

, or alternatively closer to

archosaurs Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avi ...

such as

crocodilians 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 re ...

and

dinosaurs 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 ...

. In the 1980s,

cladistics Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

helped to clarify some aspects of reptile classification, and analyses by

Jacques Gauthier Jacques Armand Gauthier (born June 7, 1948 in New York City) is an American vertebrate paleontologist, comparative morphologist, and systematist, and one of the founders of the use of cladistics in biology. Life and career Gauthier is the so ...

, and Susan Evans found substantial evidence that "prolacertiforms" were

archosauromorphs Archosauromorpha (Greek for "ruling lizard forms") is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs (such as crocodilians and dinosaurs, including birds) rather than lepidosaurs (such as tuataras, liz ...

(closer to archosaurs) rather than lepidosauromorphs (closer to lizards). Some of these analyses featured or mentioned ''Boreopricea''. Benton (1985) noted that ''Boreopricea'' was probably a prolacertid, but differed from ''Prolacerta'' due to the shape of its nasal and

bones. Evans (1988) placed ''Boreopricea'' as an intermediate branch between ''Prolacerta'', which was closer to the base of the "prolacertiform" group, and ''Macrocnemus'', which was closer to the most derived and bizarre "prolacertiforms", the tanystropheids. The classification of ''Boreopricea'' and "prolacertiforms" in general was given further scrutiny in 1997. Benton & Allen's redescription of the genus involved a phylogenetic analysis which found that ''Boreopricea'' was the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to ''Prolacerta'', at least when superfluous and unstable data was cleared. ''Macrocnemus'' was not found to be close to either taxon; instead it was placed closer to the tanystropheids. Nour-Eddine Jalil performed a very similar study that year, as part of his description of the African "prolacertiform" ''

Jesairosaurus ''Jesairosaurus'' is an extinct genus of early archosauromorph reptile known from the Illizi Province of Algeria. It is known from a single species, ''Jesairosaurus lehmani''. Although a potential relative of the long-necked tanystropheids, this ...

''. In contrast to Benton & Allen, Jalil's study placed ''Boreopricea'' deep within Tanystropheidae and unrelated to ''Prolacerta''. Some traits of ''Boreopricea'', such as a reduced posterior process of the jugal, were shared by both ''Prolacerta'' and tanystropheids. ''Boreopricea'' shared certain adaptations of the hands and feet with only tanystropheids, yet the shape of its scapula was closer to that of ''Prolacerta''. A landmark study by David Dilkes in 1998 found that ''Prolacerta'' was more closely related to

archosauriforms Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthi ...

rather than tanystropheids, dissolving the concept of a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

"Prolacertiformes" (i.e. a group where ''Prolacerta'' and tanystropheids had a common ancestor to the exception of archosaurs). ''Boreopricea'' would not be analyzed under this new framework until 2016, when it was restudied by

. Ezcurra did not consider ''Boreopricea'' close to tanystropheids, instead he found that it was an archosauriform relative, nearly as close as ''Prolacerta''. Some features visible in ''Boreopricea'' which justify this placement include the presence of mammillary processes and a heavily twisted humerus. Ezcurra also named a new group, Crocopoda, which includes all archosauromorphs closer to archosaurs than to tanystropheids. ''Boreopricea'' was part of this new grouping, which also included

rhynchosaurs Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs ...

allokotosaurs Allokotosauria is a clade of early archosauromorph reptiles from the Middle Triassic, Middle to Late Triassic known from Asia, Africa, North America and Europe. Allokotosauria was first described and named when a new monophyletic grouping of spec ...

, and various other archosauriform-like reptiles, such as ''Prolacerta''. The following cladogram is based on Ezcurra's 2016 study. A 2017 study by

Adam Pritchard Adam; el, Ἀδάμ, Adám; la, Adam is the name given in Genesis 1-5 to the first human. Beyond its use as the name of the first man, ''adam'' is also used in the Bible as a pronoun, individually as "a human" and in a collective sense as ...

Sterling Nesbitt Sterling Nesbitt (born March 25, 1982, in Mesa, Arizona) is an American paleontologist best known for his work on the origin and early evolutionary patterns of archosaurs. He is currently an associate professor at Virginia Tech in the Department of ...

slightly shifted the position of ''Boreopricea'', placing it closer to

rather than ''Prolacerta'' and archosauriforms.

Paleoecology

Ustmylian (or Ustmylskian) layers of Russian

biostratigraphy Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock Stratum, strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictiona ...

record a lakeside environment filled with animals recovering and diversifying after the Permian-Triassic extinction event, the greatest mass extinction in the history of the earth. The most common fossils at this time and place were freshwater amphibians such as '' Wetlugasaurus malachovi'', ''

Vladlenosaurus alexeyevi ''Vladlenosaurus'' is an extinct genus of capitosaur from Russia. It lived during the late Vetlugian (Early Triassic). Based on the type of deposits it was found in, ''Vladlenosaurus'' probably inhabited lacustrine, or lake, habitats. The type s ...

'', '' Vyborosaurus mirus'', and ''

Angusaurus ''Angusaurus'' is an extinct genus of trematosaurian temnospondyl within the family Trematosauridae. See also * Prehistoric amphibian * List of prehistoric amphibians This list of prehistoric amphibians is an attempt to create a comprehensive li ...

''. On land, the small omnivore niche was filled by a diverse assortment of endemic

procolophonids Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Antarc ...

, including '' Timanophon raridentatus'', '' Orenburgia bruma'', and '' Lestanshoria massiva''. The large predator niche was probably filled by early

such as '' Chasmatosuchus magnus'' and '' Tsylmosuchus jakovlevi''. These layers also preserved fossils of '' Scharschengia'', which may be one of the earliest rhynchocephalians (

tuatara Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and m ...

relatives). ''Boreopricea funerea'' probably filled a small carnivore niche alongside mammal-like therocephalians as well as '' Microcnemus efremovi'', a reptile which was similar to and probably closely related to it.

References

{{Taxonbar, from=Q62959066 Prehistoric archosauromorphs Prehistoric reptile genera Olenekian genera Early Triassic reptiles of Europe Triassic Russia Fossils of Russia Fossil taxa described in 1978