Araripegryllus romualdoi Freitas, de Moura & Saraiva, 2016

Heads, Sam W., 2018, On the status of Araripegryllus romualdoi (Insecta: Orthoptera: Grylloidea) from the Cretaceous Santana Formation of Brazil, Zootaxa 4486 (1), pp. 83-84 : 83

Araripegryllus romualdoi Freitas, de Moura & Saraiva, 2016 NOMEN DUBIUM

2016 Araripegryllus romualdoi Freitas, de Moura & Saraiva , p. 2116–2117, fig. 3.

Holotype. MPSC 1846, part and counterpart, Museu de Paleontologia da Universidade Regional do Cariri ( URCA) de Santana do Cariri.

Type locality. Araripe Geopark, 3 km from Santana do Cariri, Ceará, Brazil.

Type horizon. Romualdo Member, Santana Formation; Albian, Lower Cretaceous.

Remarks. The original diagnosis of A. romualdoi reads: “pronotum wider than the head, antennae coming from the center of the head, elongated cerci, robust femurs [sic], non-elongated body and forewings with length over 5 mm ” ( Freitas et al., 2016, p. 2116). None of the characters used can be considered diagnostic. Problems are as follows: (1) the pronotum is wider than the head in all Araripegryllus (with the possible exception of the poorly defined A. megacephalus Martins-Neto, 1991 ) and so, this character is not unique to A. romualdoi ; (2) the head is too poorly preserved in the holotype to determine the true position of the antennae; (3) elongate cerci are present in all Araripegryllus so this character is certainly not unique to A. romualdoi ; (4) it is unclear which femora the authors are referring to in the diagnosis, but in their description they refer specifically to the hind femora which are, of course, robust in all orthopterans; (5) it is unclear what the authors mean by “non-elongate body” but body length can certainly not be considered diagnostic at the species level in Araripegryllus ; and (6) it is unclear if the tegmina (forewings of the authors) are even preserved in the holotype as no structures present in the photograph (Freitas et al.’s fig. 3) can clearly be identified as such. With these shortcomings and the very poor preservation of the holotype in mind, it is impossible to properly diagnose A. romualdoi and the species must be regarded as a nomen dubium.

Freitas et al. assigned A. romualdoi to Araripegryllus Martins-Neto, 1987 ( Gryllidae : Gryllospeculinae ), a genus comprising seven species from the Crato Formation ( Martins-Neto, 1991; Heads & Martins-Neto, 2007) and one questionably assigned species from the Lower Cretaceous of southern England ( Gorochov et al., 2006). Assigning A. romualdoi to Araripegryllus is problematic because the diagnosis of the genus is based entirely on male tegminal characters. In particular, Araripegryllus is defined by the presence of a distinctive, elongate, curved cell that surrounds the anterior part of the speculum. Since no tegminal characters can be observed in A. romualdoi —the tegmina being absent or very fragmentary and poorly preserved—even tentative assignment to Araripegryllus is impossible. Moreover, the assignment of the specimen to Gryllidae is itself questionable since a placement in Baissogryllidae cannot be ruled out with certainty. Therefore, A. romualdoi can, at best, be regarded as Grylloidea incertae sedis.