The stomatopods, or mantis shrimps, are malacostracan crustaceans of the
subclass Hoplocarida. Extant hoplocarids belong to the order Stomatopoda and
suborder Unipeltata, comprising the extinct, stem-lineage pseudosculdids and
sculdids, and the crown group. Cladistic analysis including most or all genera
of the unipeltatan families, and rooted to the extinct Tyrannophontidae,
resulted in four most-parsimonious cladograms. The present results are more
highly resolved and more robust than previous studies as the result of: more
precise identification of suitable outgroups; a more complete outgroup data
set, lessening the impact of missing data; and increased taxonomic sampling.
The results largely support the existing five-superfamily classification, but
as with two recent cladistic studies, Gonodactyloidea was polyphyletic.
Gonodactyloidea is the basal crown-group superfamily and comprises mostly
‘smashers’. Two clades of ‘spearers’, Eurysquillidae
and Parasquillidae, previously considered gonodactyloids, are more closely
related to the Squilloidea and are referred to new superfamilies. The familial
classification within Lysiosquilloidea is modified. Rather than deriving the
‘smashers’ from a long line of ‘spearers’, the present
analysis suggests that the Unipeltata diverged in two broad directions from
the outset. Hence, the gonodactyloid ‘smashers’ became specialised
for hard substrates, and the remainder diversified into the other modern
superfamilies, evolving more efficient ‘spearing’ claws, and
occupying soft substrates.
The impact of allometry on vomer shape and its implications for the taxonomy and cranial kinesis of crown-group birds
