Reconstruction of Gerarus danielsi from Burnham (1983).

Belongs within: Orthoptera.

The Geraridae are a group of insects known from the Upper Carboniferous. Members of the type genus, Gerarus, had an expanded spinose prothorax; prothoraces of other genera are unknown (and the monophyly of the larger Geraridae was regarded as questionable by Béthoux & Nel, 2002).

See also: All about Gerarus.

Characters (from Burnham 1983): Head small and probably mobile; antennae filamentous. Prothorax elongate, flask-shaped, and distinctively spinose. Fore and hind wings similar in size and shape, but markedly different in venation. Forewing length 35-55 mm, apparently not coriaceous; costal area broad in basal region, SC simple, terminating in C; R parallel to SC, terminating at wing apex; RS originating from base of R near midpoint of wing; M either anastomosing with RS for a short distance or connecting to it by a cross-vein; CUA strongly developed, arising from base of M; CUP forked, arising independently from wing base. Hind wing length 30-48 mm; costal area not as broad as in forewing; SC simple, terminating in C; R parallel to SC, terminating at wing apex; RS pectinate, arising from R near wing base; M forked, arising near base of RS; CUA and CUP simple and parallel to one another; CUA arising from base of RS near M, CUP arising independently from wing base; anal area unusually reduced; cross veins abundant in both fore and hind wings. Legs cursorial; tarsi five-segmented. Abdomen cylindrical.

<==Geraridae [Gerarina, Gerarodea]
    |--Genentomum Scudder 1885 R02, BN02
    |    `--G. validum Scudder 1885 BN02
    |--Progenentomum Handlirsch 1906 R02, BN02
    |    `--P. carbonis Handlirsch 1906 BN02
    |--Nacekomia Richardson 1956 R02, BN02
    |    `--N. rossae Richardson 1956 BN02
    |--Anepitedius Handlirsch 1911 R02, BN02
    |    `--A. giraffa Handlirsch 1911 BN02
    |--Osnogerarus Kukalová-Peck & Brauckmann 1992 BN02
    |    `--*O. trecwithiensis Kukalová-Peck & Brauckmann 1992 BN02
    |--Cantabrala Kukalová-Peck & Brauckmann 1992 R02, BN02
    |    `--C. gandli Kukalová-Peck & Brauckmann 1992 BN02
    `--Gerarus Scudder 1885 BN02
         |--*G. vetus Scudder 1885 BN02
         |--G. bruesi (Meunier 1909) [=Archaeacridites bruesi, Sthenaropoda bruesi] BN02
         |--G. collaris Handlirsch 1906 BN02
         |--G. danielsi Handlirsch 1906 BN02
         `--G. fisheri (Brongniart 1885) BN02

*Type species of generic name indicated


[BN02] Béthoux, O., & A. Nel. 2002. Venation pattern and revision of Orthoptera sensu nov. and sister groups. Phylogeny of Palaeozoic and Mesozoic Orthoptera sensu nov. Zootaxa 96: 1-88.

Burnham, L. 1983. Studies on Upper Carboniferous insects: I. The Geraridae (order Protorthoptera). Psyche 90 (1-2): 1-57.

[R02] Rasnitsyn, A. P. 2002. Infraclass Gryllones Laicharting, 1781. The grylloneans (=Polyneoptera Martynov, 1938). In History of Insects (A. P. Rasnitsyn & D. L. J. Quicke, eds) pp. 254-262. Kluwer Academic Publishers: Dordrecht.

No comments:

Post a Comment

Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="">FoS</a> = FoS