''Antarcticarcinus'' is an extinct genus of late

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

(

Gzhelian The Gzhelian ( ) is an age in the ICS geologic time scale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from to Ma. It follows the Ka ...

) to early

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

(

Asselian In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between and million years ago (Ma ...

)

euthycarcinoid Euthycarcinoidea are an enigmatic group of extinct, possibly amphibious arthropods that ranged from Cambrian to Triassic times. Fossils are known from Europe, North America, Argentina, Australia, and Antarctica. Description The euthycarcinoid bod ...

s from the Pagoda Formation of Antarctica. The genus contains a single species, ''Antarcticarcinus pagoda''.

Description

''Antarcticarcinus'' was at least 4 cm long (the most complete fossil only preserves the head and postabdomen). The genus is remarkable for the unusual "wings" on its first preabdominal segment, which immediately distinguish it from any other euthycarcinoid. It is also one of the few euthycarcinoids which deviates from the typical body shape, alongside '' Arthrogyrinus'' which shows a particularly flattened tail. The rest of the body is quite typical for a euthycarcinoid, with eyes near the tip of the head and possible square-shaped mandibles, although the head may be composed of two sclerites. At least three to four dorsal

tergites A ''tergum'' (Latin for "the back"; : ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'margin'. ...

are preserved, with the first bearing the aforementioned large lateral processes. At least five ventral

sternites The sternum (: sterna) is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the sub ...

are preserved, with the first being much longer than the others. Limbs are also preserved, with them seemingly being

uniramous The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, : ...

and made of four to five box-like

podomere The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, : ...

s. A more gracile disarticulated limb has also been recorded, which may be further down the preabdomen, with a possible antenna preserved on the head. No limb setae are known.

Etymology

''Antarcticarcinus'' derives from the Greek ''karkinos'' meaning "crab", and Antarctica, the location of the fossils. The species name ''pagoda'' derives from the Pagoda Formation where the fossils were found.

References

{{Taxonbar, from=Q131403440 Fossils of Antarctica Taxa described in 2017 Permian genus extinctions Gzhelian life Asselian life Prehistoric arthropod genera