A fossil found in northeastern Brazil confirmed that the splay-footed cricket of today has at least a 100 million-year-old pedigree. Credit: Hwaja Goetz
Researchers have discovered the 100 million-year-old
ancestor of a group of large, carnivorous, cricket-like insects that still live
today in southern Asia, northern Indochina, and Africa.
The new find, in a limestone fossil bed in northeastern Brazil,
corrects the mistaken classification of another fossil of this type and reveals
that the genus has undergone very little evolutionary change since the Early
The findings are described in a paper in ZooKeys.
“Schizodactylidae, or splay-footed crickets, are an unusual
group of large, fearsome-looking predatory insects related to the true
crickets, katydids and grasshoppers, in the order Orthoptera,” said Univ. of Illinois entomologist and lead author Sam
Heads, of the Illinois Natural History Survey. “They get their common name from
the large, paddle-like projections on their feet, which help support their large
bodies as they move around their sandy habitats, hunting down prey.”
Although the fossil is distinct from today’s splay-footed
crickets, its general features differ very little, Heads said, revealing that
the genus has been in a period of “evolutionary stasis” for at least the last
100 million years.
Other studies have found that the region where the fossil
was found was most likely an arid or semi-arid monsoonal environment during the
Early Cretaceous Period, Heads said, “suggesting that the habitat preferences
of Schizodactylus have changed little in over 100 million years.”
Léa Leuzinger, a graduate student at the Univ. of Fribourg,
is a co-author on the study.