Latedactylus longapedi, Zheng & Cao & Gu, 2023

Zheng, Chengjie, Cao, Chengquan & Gu, Jun-Jie, 2023, A new genus and a new species of pygmy mole cricket from mid-Cretaceous amber in North Myanmar (Orthoptera: Caelifera: Tridactyloidea), Zootaxa 5339 (3), pp. 296-300 : 297-299

Latedactylus longapedi sp. nov.

urn:lsid:zoobank.org:act:C58A76DF-B65A-4469-A673-5146191B1CF6

Material. Holotype, LNU-5, gender unknown, a nearly complete specimen, including the head, prothoracic leg, mesothoracic leg, metathoracic leg and terminal abdomen, the specimen is in fair condition, a crack through the body.

Diagnosis. As for the genus.

Etymology. The specific epithet is from the Latin ‘longa’ and ‘ped’, used to describe the well-developed metatarsus.

Locality and horizon. Hukawng Valley, Kachin Province, Myanmar; lowermost Cenomanian, Upper Cretaceous.

Description. Holotype, LNU-5 ( Fig. 1 ), gender unknown, body 3.05 mm long measured from the head to the abdominal apex; pronotum 0.6 mm long at midline; profemur 0.5 mm long; protibia 0.4 mm long; mesofemur 1.0 mm long; mesotibia 1.0 mm long; metafemur 2.2 mm long; metatibia 2.0 mm long. The specimen is in fair condition, a crack through the body.

Head. The head dark brown; compound eye large and well developed; ocelli apparently presence; antennae moniliform, 9-segmented visible, flagellomere widening towards apex, inserted beneath the lower margin of compound eye; hypognathous, capsulate ( Fig. 1A, B ).

Thorax. The thorax dark brown; pronotum large, shield-like, extending posteriorly to entirely cover the mesonotum; posterior margin broadly rounded; tegmen and hindwing absent ( Fig. 1A, B ).

Leg. Prothoracic leg brown; profemur slender with long externally spaced ventral setae, distinctly shorter than mesothoracic leg; protibia robust, inflated distally with a sparse covering of strong setae and four strong teeth; protarsus two-segmented, slender, with second segment longer than first; basitarsus short; apical tarsomere elongate, slightly curved, formation of two claws. Mesothoracic leg light in colour; mesothoracic leg about twice as long as the prothoracic leg, with sparse setae on the ventral margin; mesofemur thick, basally narrow and apically broad; mesotibia brown, apex with light coloration; mesotibia approximately twice as long as protibia, strongly inflated, with dorsal and ventral setae; mesotarsus almost identical to the protarsus ( Fig. 1A, B ). Metathoracic leg dark brown, apparently saltatorial; metafemur almost as long as abdomen and greatly inflated along its entire length, with prominent dorsal carina; genicular lobe large and well-developed; metatibia slightly shorter than metafemur, very slender, with tiny spines on the dorsal margins, without setae, lacking swimming plates, with two small subapical spurs and two flattened apical spurs; metatarsus one-segmented, about three times as long as apical spurs, apex saber-like, without subapical denticular processes ( Fig. 1E, F ).

Abdomen. The abdomen dark brown, with sparse and long setae; crushed, mostly obscured by metafemur; cercus long, two-segmented, with sparse long setae, the second segment cylindrical, longer and more slender than the first; paraproctal lobe cone-shaped and slender, thinner than the first segment of the cercus, with sparse and long setae ( Fig. 1C, D ).

Remarks. Latedactylus longapedi gen. et sp. nov. can be assigned to Tridactylinae Günther, 1979 by two-segmented cercus and metatarsus without subapical denticular process.

This new genus differs from Archaeoellipes Heads, 2010 and Ellipes Scudder, 1902 by metatarsus is much longer than apical spurs. Latedactylus gen. nov. is similar to Phyllotridactylus Xu et al., 2022 with matetibia lacks swimming plates and metatarsus is much longer than apical spurs. But this new genus differs from Phyllotridactylus by the following characters: the cylindrical second segment of cercus is longer and more slender than the first, while that of Phyllotridactylus is much shorter than the first segment of cercus; metatersus is about three times as long as apical spurs, while that of Phyllotridactylus is about twice as long as apical spurs; and slender paraproctal lobe is thinner than the first segment of the cercus, while that of Phyllotridactylus is almost as thick as cercus. Therefore, Latedactylus gen. nov. can be separated from all known genera of Tridactylinae .

Figures

FIGURE 1. Holotype (LNU-5) of Latedactylus longapedi sp. nov. holotype; (A) photograph of the habitus in the dorsal‐lateral view, (B) line drawing of the habitus, (C) photograph of the terminal abdomen in dorsal view, (D) line drawing of the terminal abdomen, (E) photograph of the right metatarsus, (F) line drawing of the right metatarsus. The abbreviations of the characters are as follows: protibia, pt; mesothoracic leg, meso; cercus, ce; paraproctal lobe, pptl; metatarsus, mt; apical spur, asp; subapical spur, sasp.