Rolfe
W.D.I. & Dzik, J. 2006. Angustidontus,
a Late Devonian pelagic predatory crustacean. Transactions of the Royal Ssociety of
Edinburgh
: Earth Sciences 97, 75-96.
Abstract.
Restoration
of the morphology of Angustidontus
seriatus Cooper, 1936 based on complete specimens from the Famennian of
Nevada and Poland, supports its affinity to the coeval alleged decapod Palaeopalaemon
and suggests eocarid (possibly also peracarid) affinities. Predatory
adaptation of the thoracopods and the relatively short pereion make this
crustacean only superficially resemble the archaeostomatopod hoplocarids,
because the large grasping appendages of Angustidontus
represent the first, rather than second, maxillipeds and acted in the opposite
direction: downward. Another similar adaptation of the antennae in the Viséan
Palaemysis suggests a widespread
adaptation to predation among early eumalacostracans. The large sample
collected from the Woodruff Formation of Nevada permits biometric
characterisation of the grasping maxillipeds of Angustidontus, showing that their highly variable morphology should
not be used to define species. All previously described species are therefore
here synonymised with A. seriatus.
Differences in gnathobases of mandibles found in articulated specimens in
Nevada, and associated with isolated maxillipeds and articulated specimens
possibly representing another unnamed species in Poland, suggests that such
mandibles may eventually prove to be taxonomically more significant.
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