1046
Journal of Paleontology
Figure 9. Holotype of ‘Liassophlebia’ clavigaster Tillyard, 1925 (NHMUK I.10433), Strensham, Worcestershire (Rhaetian), photograph.
quite distinct, directed toward posterobasal margin of wing, with AA ending within it. Cubital area broad with ~ 5 or 6 rows of cells between CuA and posterior wing margin. Anal area broad with two rows of large cells. Anal margin rounded, without any angle; no anal triangle (female).
Remarks.—The original description and figure (Carpenter, 1969) shows an almost complete and supposedly well-preserved fossil. However, the type specimen (Fig. 8) is not as well- preserved with most of the apical half of the wing missing, although fortunately most of the major veins are preserved though slightly warped by the structure of the rock. The numerous secondary antenodal crossveins figured by Carpen- ter (1969, fig. 1) are not discernible. The pattern of the long- itudinal veins, i.e., postdiscoidal space not narrowed and RP3/ 4 not parallel to IR2, corresponds to Liassophlebiidae and Selenothemistidae. However, the shape of the discoidal cell differs from that of liassophlebiids in that it is relatively short and without any trace of division into a hypertriangle and discoidal triangle. The probable absence of secondary antenodal crossveins and veins in the basal area between RA and RP also supports attribution to the Selenothemistidae. The quite well-defined CuA2, curved toward the posterobasal side of the wing, is very particular and probably is an autapomor- phy of the genus.
Odonata incertae sedis, fam. indet. ‘Liassophlebia’ clavigaster Tillyard, 1925
1925 Liassophlebia (?) clavigaster Tillyard, p. 19, pl. 3, fig. 9, text-fig. 5.
1939 (Anisozygopteron) clavigaster; Handlirsch, p. 29.
1978 Liassophlebia clavigaster; Lindley, p. 344. 1993 Liassophlebia (?) clavigaster; Nel et al., p. 142, fig. 109.
Holotype.—NHMUK I.10433 (Fig. 9), ‘Insect limestone’ of the Pseudomonotis beds (Penarth Group, Lilstock Formation); Late Triassic, Rhaetian; Strensham, Worcestershire.
Remarks.—This specimen and the other identified as this species (NHMUK I.475) are known only from abdominal segments. Liassophlebiid higher taxonomy is based on wings so it is impossible to attribute this specimen to a genus or family. Therefore, we consider this species to be incertae sedis at those levels until a better-preserved specimen allows identification.
‘Liassophlebia’ hopei (Brodie, 1845) 1845 Libellula hopei Brodie, p. 71, pl. 10, fig. 3.
Figure 10. Holotype of ‘Liassophlebia’ hopei (Brodie, 1845) (OUMNH J.55084); Strensham, Worcestershire (Rhaetian); photograph.
1892 Libellula hopei; Woodward, p. 195. 1879 Libellula hopei; Goss, p. 129. 1850 Petalura liassina (Strickland); Hagen, p. 359. 1850 Heterophlebia hopei; Selys-Longchamps and Hagen, p. 359 (footnote).
1906 (Anisozygopteron ?) hopei; Handlirsch, p. 470. 1939 (Anisozygopteron) hopei; Handlirsch, p. 29. 1925 Liassophlebia (?) hopei; Tillyard, p. 19. 1993 Liassophlebia hopei; Nel et al., p. 143.
Holotype.—OUMNHJ.55084 a and b, ‘Insect Limestone’ of the Pseudomonotis beds (Penarth Group, Lilstock Formation); Rhaetian; Strensham, Worcestershire.
Remarks.—Same reasoning as for ‘Liassophlebia’ clavigaster, above.
Discussion
Examination of the fossil material from the Late Triassic and Early Jurassic of England has led to several major changes to the taxonomy of Liassophlebiidae and changes to the diversity estimates of insects across the TJB. The new family Angloph- lebiidae is tentatively erected for a specimen previously attrib- uted to the liassophlebiid species Liassophlebia gigantea by Zeuner (1962). This specimen is only a fragment of a wing, and it is expected that future changes to the taxonomy of this family will be required as and when better-preserved specimens are found. However, the characters that are preserved are of suffi- cient uniqueness that it is important to draw attention to the specimen. This taxon is of particular interest because it appears to exhibit characters traditionally attributed to both fore- and hindwings, respectively narrow cubito-anal area vs. discoidal cell basally close and nearly divided into two parts by an incomplete crossvein. Rossiphlebia n. gen. is erected for a species previously
attributed to Liassophlebia jacksoni by Zeuner (1962). This species is clearly not attributable to Liassophlebia because the subdiscoidal space is subdivided into two large cells by a branch of AA. This genus is particularly interesting because it seems to exhibit characters of both Liassophlebiidae and Hetero- phlebiidae. As the taxonomy of these groups is revised, it is also
important to consider the bigger picture and the effects of such findings on previous phylogenies (e.g., Nel et al., 1993). With the new characters described since 1993, the topography of a Jurassic Odonata phylogeny would probably look much different. Two specimens—a forewing and a hindwing—were ori- ginally attributed to Liassophlebia batheri by Tillyard (1925).
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