Apankura
Extinct genus of euthycarcinoid
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Apankura is an extinct genus of Cambrian euthycarcinoids from the Santa Rosita Formation of Argentina. The genus contains a single species, Apankura machu.[1] It was at one point the only Cambrian euthycarcinoid. However, Mosineia and Mictomerus are likely older.[2]
| Apankura Temporal range: | |
|---|---|
| |
| Reconstruction of A. machu | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subclass: | †Euthycarcinoidea |
| Genus: | †Apankura Vaccari et al., 2004 |
| Species: | †A. machu |
| Binomial name | |
| †Apankura machu Vaccari et al., 2004 | |
Description
Apankura is roughly 4 centimetres (1.6 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.[1]
Etymology
Apankura derives from a Quechua word meaning "crab", whilst machu derives from a word meaning "grandfather" in reference to the age of the fossils.[1]