Apankura
{{Short description|Extinct genus of euthycarcinoid}}
{{Speciesbox
| fossil_range = {{fossil range|Furongian}}
| display_parents = 2
| image = Apankura.png
| image_upright =
| image_caption = Reconstruction of A. machu
| genus = Apankura
| parent_authority = Vaccari et al., 2004
| species = machu
| authority = Vaccari et al., 2004
}}
Apankura is an extinct genus of Cambrian euthycarcinoids from the Santa Rosita Formation of Argentina. The genus contains a single species, Apankura machu.{{cite journal |last1=Vaccari |first1=N. E. |last2=Edgecombe |first2=G. D. |last3=Escudero |first3=C. |title=Cambrian origins and affinities of an enigmatic fossil group of arthropods |journal=Nature |date=July 2004 |volume=430 |issue=6999 |pages=554–557 |doi=10.1038/nature02705}} It was at one point the only Cambrian euthycarcinoid. However, Mosineia and Mictomerus are likely older.{{cite journal |last1=Collette |first1=Joseph H. |last2=Hagadorn |first2=James W. |title=Three-dimensionally preserved arthropods from Cambrian Lagerstätten of Quebec and Wisconsin |journal=Journal of Paleontology |date=July 2010 |volume=84 |issue=4 |pages=646–667 |doi=10.1666/09-075.1}}
Description
Apankura is roughly {{convert|4|cm|in}} long, and has large mandibles, a trait previously unknown from euthycarcinoids. The antennae are uniramous like other euthycarcinoids, with a possible buccal complex present behind the mandibles. No post-mandibular oral appendages are present. The pre-abdomen is composed of five tergites, with 11 uniramous limb pairs, with the tergites showing "segment decoupling" where there are more limbs than tergites. The pre-abdomen also has 11 sternites, each roughly 3 times wider than long. The pre-abdominal limbs match other euthycarcinoids, although they taper distally and lack setae. The apodemes are preserved as several dark rods. The post-abdomen is incomplete but composed of at least six segments, all lacking limbs, with the gut preserved as a dark line in the centre. A circular structure on the second post-abdominal segment is of unclear function, although it may be a gonopore. Apankura is unique among euthycarcinoids due to the reduced anterior pre-abdominal limbs, a longer post-abdomen and relatively few limb podomeres.