Paleontologists have described a new species of cricket found in a piece of Cretaceous-period amber from northern Myanmar.
Qiongqi crinalis: (A) habitus in dorsal view; (B) habitus in ventral view; (C) head in dorsal view; (D) thoracic legs. Scale bars – 0.5 mm. Image credit: Yuan et al., doi: 10.11646/zootaxa.5330.1.9.
The newly-described species is named Qiongqi crinalis and represents a family of crickets called Trigonidiidae.
“Trigonidiidae is a large family of Grylloidea (crickets) widely distributed in the world,” said Sichuan Agricultural University entomologist Wei Yuan and colleagues.
“This family consists of two subfamilies (Nemobiinae and Trigonidiinae) including 125 genera and 1,034 species.”
“Trigonidiidae are characterized by the following characteristics: tiny size with strong setae over the entire body; frons is broader than antennal scape; apical and subapical spurs are present; and the metabasitarsomeres are not serrulated except for one apical inner and one apical outer spine.”
“Trigonidiinae, unlike Nemobiinae (most Nemobiinae live and scavenge in the leaf litter), are found in a limited number of environments and survive mainly on plants, they are easily distinguished by their triangular head, pronotum smaller than the head, serrated claws, protibia with a single spur, metatibia with three sets of subequal subapical spurs and blade-shaped ovipositor.”
According to the authors, around 10 extinct species of crickets are known to science.
“Among them, two species from Burmese amber (Birmaninemobius hirsutus and Curvospurus huzhengkun) remain without assignment to any subfamily,” they said.
“These two species are the stem group of Trigonidiidae and exhibit unique combination characteristics between Trigonidiinae and Nemobiinae.”
The amber specimen with Qiongqi crinalis dates back some 99 million years.
It was collected from the famous amber deposits at Noije Bum, near Tanai in the Hukawng Valley of northern Myanmar.
“On the basis of its compound eyes protruding in dorsal view, frons wider than scape, and body with robust setae, Qiongqi crinalis can be assigned to Trigonidiidae,” the researchers said.
“This new species share with Trigonidiinae species a pronotum smaller than the head in dorsal view and the protibia having only one apical spur.”
“Meanwhile, it is similar to Nemobiinae in lack of serrated claws, the second tarsomeres are neither widened nor flat, metatibia has more than three pairs of subapical spurs and proximal subapical spurs are much shorter than distal subapical spurs.”
“Qiongqi crinalis can be distinguished from these two subfamilies by its unusual head (short clypeus and exposed mandible), metabasitarsomere serrulated and the presence of numerous strong setae and hairs throughout the body.”
Qiongqi crinalis had a relatively big head and compound eyes, with an exposed, rather long jaw.
These characters are much more similar to some carnivorous insects than to the typical cricket.
Nevertheless, all living crickets are omnivorous, there is no concrete evidence of cricket predation.
“Although it is hard to verify the feeding habits of this species, Qiongqi crinalis provides us with new knowledge of the head morphology of ancient crickets,” the scientists said.
The findings were published in the journal Zootaxa.
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Wei Yuan et al. 2023. A new genus and a new species of Trigonidiidae (Orthoptera: Grylloidea) from north Myanmar amber. Zootaxa 5330 (1): 141-146; doi: 10.11646/zootaxa.5330.1.9
