Frog Crabs, Raninoidia, are well represented in the fossil
record across much of the globe in the Late Cretaceous and Cenozoic, but poorly
recorded from the Early Cretaceous, when the group is thought to have
originated. For a long time the majority of early Frog Crabs known were from
Eurasia, leading to suggestions that they may have originated at high northern
latitudes, but a number of new specimens have recently been reported from
Colombia, leading to a re-evaluation of the groups origins, with the
possibility that they may have originated in equatorial South America.
In a paper published in the journal Scripta Geologica in October
2014, Javier Luque of the Department of Biological Sciences at the Universityof Alberta and the Smithsonian Tropical Research Institute described a new
species of Frog Crab from the Early Cretaceous Paja Formation of the Department
of Santander in Colombia.
The new species is named Bellcarcinus aptiensis,
where ‘Bellcarcinus’ means ‘Bell’s
Crab’ honouring palaeontologist Thomas Bell (1792-1880) for his work on fossil
Frog Crabs, and ‘aptiensis’ means
‘from the Aptian’, in reference to the Aptian Age (~125-113 million years
ago), from which the fossils derive.
Bellcarcinus aptiensis, dorsal carapace. Luque (2014).
The new species is described from four specimens, ranging from 6.6
mm to 13 mm in length and from 8 mm to 16.1 mm in width. Luque suggests that Bellcarcinus aptiensis is probably a
member of the Orithopsidae, making it the earliest occurrence of a
group already thought to be one of the earliest Frog Crab families to appear,
but notes that it also shows affinities to the Necrocarcinidae.
See also…
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having different carapace structures and numbers of fused segments, but all are
quite small, which gets the...
Freshwater Crabs of the genus Geothelphusa, are known from Taiwan, the Ryukyu Islands and the main islands of Japan. To date 55 species have been described, 38 of which are found in Taiwan and its adjacent islands, fifteen are found in the Ryukyus and...
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