AMMONITES AND NAUTILOIDS OF WADl HAJAR 



51 



because distinctive characters are only attained at diameters well in 

 excess of 100 mm. These two species are the commonest 

 Pachysphinctes in southern Yemen, and after consideration of the 

 difficult problems of nomenclature, they are described below as 

 Pachysphinctes /jarMp/ocMj (Waagen) (of which P. heyrichi (Futterer) 

 is probably a synonym) and P. major Spath. A few, more finely 

 ribbed specimens are described as P. inahokondobeyrichi (Dietrich). 

 As pointed out by Verma & Westermann (1984: 38), excessive 

 splitting of both genera and species by Spath ( 193 1 ) in his revision 

 of the Cutch fauna, make it likely that many of his new species are 

 minor variants of P. bathyplocus and P. major, and some of the 

 probable synonymies are indicated below, though proper revision 

 must await the availability of single horizon collections from Cutch. 

 The Yemeni collections of Pachysphinctes from single horizons at 

 Naifa Cliff and Al Ma'abir show a moderate amount in variation in 

 whorl proportions and rib-density, that is certainly sufficient to 

 embrace several of Spath's species at Cutch. 



Interpretation of cutch pachysphinctes. Waagen described 

 two common species from the Middle Katrol Beds of Cutch, which 

 he identified asPerisphinctes torquatus (J. de C. Sowerby) (Waagen, 

 1875: 191, pi. 54) and P bathyplocus sp. nov. (Waagen, 1875: 192, 

 pi. 50, fig. 1). In redescribing these two species, Spath (1931: 466) 

 noted that it was very difficult to identify the large example of 

 Waagen's pi. 54 with the much smaller holotype of Sowerby's 

 Ammonites torquatus, which he refigured (Spath, 1931: pi. 76, fig. 

 4), so he proposed the replacement name Pachysphinctes major 

 Spath (193 1 : 467, 489) for Waagen's pi. 54 and other specimens that 

 were available to Waagen and himself. As Spath did not designate a 

 holotype, the original ofWaagen's pi. 54 is here designated lectotype 

 of P. major. Spath had that lectotype on loan, and after examining it 

 he wrote 'Waagen's large example [ie. Waagen, pi. 54] is entirely 

 septate and the suture-lines are quite distinct in various places on the 

 outer whorl, so his remarks about the lobes not being visible must be 

 due to a slip" (that remark was 'The lobes are not visible on any part 

 of the specimens at hand' (Waagen, 1875: 192)). Again, in his 

 redescription ofWaagen's species P. bathyplocus, Spath (1931: 493) 

 wrote 'Waagen's description was based largely on specimens other 

 than the figured type' . Spath also had the original ofWaagen's pi. 50, 

 fig. 1 on loan (BM C. 52480 is a plaster-cast), and he was alluding to 

 the many differences between Waagen's descripdons and the single 

 specimens that he figured to illustrate the two species. Spath did not 

 claim, however, that the two figured specimens or their captions had 

 been transposed at some stage, even though there is a clear precedent 

 for such a mistake in Waagen's (1875) monograph (the labels and 

 captions of his plates 40 and 41 were transposed, as is abundantly 

 clear when text and plates are compared, as was pointed out by Spath 

 (1931: 374), who described it as 'the wrong numbering ofWaagen's 

 plates'). The case for the transposition of the capfions of Waagen's 

 pi. 50, fig. 1 and pi. 54 is less clear: his description of P. bathyplocus 

 is of a species that develops massive depressed whorls and large 

 coarse primary ribs at sizes larger than 150 mm diameter, which 

 together with his measurements of a 210 mm diameter specimen, fit 

 the example figured in pi. 54. The original of pi. 50, fig. 1 is a better 

 match for his description of Perisphinctes torquatus, though that 1 33 

 mm diameter figured specimen is not one of the three for which he 

 gave measurements. Though transposition of the figured specimens 

 or their captions is highly suggestive, the case remains unproved, 

 and rather than disrupt existing nomenclature, it has been decided to 

 leave interpretation of the two species unchanged, ie. Pachysphinctes 

 bathyplocus (Waagen) is based on its lectotype, Waagen, 1875, pi. 

 50, fig. UandP major Spath is based on its lectotype, the original of 

 Waagen's pi. 54. [To reverse the identity of these two lectotypes 



would mean applying the name P. bathyplocus to pi. 54, of which P. 

 major would then become an objective synonym (ie. based on the 

 same type specimen), and it would leave pi. 50, fig. 1 without a 

 Waagen or Spath name, for which P. beyrichi (Futterer) would 

 become available]. 



Occurrence. Tanzania, Kenya, Ethiopia, Somalia, Yemen, west- 

 ern India (Cutch), Madagascar; occurs in the Beckeri (Upper 

 Kimmeridgian) and Hybonotum (Lower Tithonian) Zones, though 

 there is some evidence that P. beyrichi {=P. bathyplocus here) first 

 occurs slightly lower, in the Eudoxus Zone in Kenya (Verma & 

 Westermann, 1984: 40). 



Pachysphinctes bathyplocus (Waagen), 1875 



Fig. 2; PI. 5, figs 1, 4; PI. 7, figs 2, 5 



1875 Perisphinctes bathyplocus Waagen: 192, pi. 50, fig. 1. 

 1894 Perisphinctes beyrichi Futterer: 9, pi. 2, figs 1-3. 

 1910 Perisphinctes ( Virgatosphinctes ?) beyrichi Futterer; Dacque: 

 14. pi. 4, fig. 2. 

 71910 Perisphinctes africanus Dacque: 17, pi. 3, fig. 2. 

 1925 Perisphinctes cf. biplicatus Uhhg; Stefanini: 144, pi. 27, 

 fig. 1. 

 71925 Perisphinctes (Pachysphinctes) africogermanus Dietrich: 

 12, text-figs 1, 2, pi. 3, fig. 1 {non fig. 2). 



1930 Torquatisphinctes bevrichi (Futterer); Spath: 55, pi. 3, fig. 

 6. 



1931 Pachysphinctes granti Spath: 492, pi. 90, fig. 6. 



1931 Pachysphinctes bathyplocus (Waagen); Spath: 493, pi. 77, 



fig. 1 ; pi. 78, fig. 6; pi. 88, fig. 1 ; pi. 93, figs 5, 9; pi, 96, fig. 



4. 

 1931 Pachysphinctes wantraensis Spath: 497, pi. 95, fig. 1. 

 71931 Pachysphinctes symmetricus Spath: 498, pi. 101, fig. 7. 

 71931 Pachysphinctes orientalis Spath: 499, pi. 100, fig. 2. 

 1959 Torquatisphinctes betsibokensis Collignon: pi. 109, fig. 



401. 

 1959 Pachysphinctes granti Spath; Collignon: pi. 1 16, fig. 443. 

 1959 Pachysphinctes marellei Collignon: pi. 1 17, fig. 444. 

 1959 Pachysphinctes trichordis Collignon: pi. 1 17, fig. 445. 

 1959 Pachysphinctes bathyplocus (Waagen), var. sparsiplicata 



Spath; Collignon: pi' 118, fig. 447. 

 71959 Torquatisphinctes adeloides Spath; Collignon: pi. 1 27, fig. 



475. 

 1984 Pachysphinctes beyrichi (Futterer); Verma & Westermann: 



39, text-fig. 4, pi. 6, figs 1, 2. 



Lectotype. The original of Waagen, 1875, pi. 50, fig. 1, here 

 designated, and refigured in PI. 5, fig. 1. 



Material. 37 specimens from the Kilya Member: 5, CA 1 147-5 1 , 

 from the upper marly part; CAl 152 from the top bed of the middle 

 Hmestone part, and 5, CAl 153-56 and C. 86964, from high in the 

 same part in Wadi Kilya; 20. CA98 1-94. SM F 1 2 1 95-97, F 1 2 1 99, 

 F. 1 2203 and F. 1 2205, from the bottom of the middle limestone part, 

 in Naifa Cliff; 5, CA726-30 from the Breadloaf Concretions in the 

 lower marly part in Wadi Arus, and CA995 from the same part in 

 Naifa Cliff. 



Description. Many of the 37 specimens referred to this species 

 are parts of single whorls in the size range 100-200 mm diameter. 

 Most are portions of body-chambers, and the largest fragment has a 

 whorl height and breadth of 70 mm and 62 mm respecively. indicat- 

 ing a diameter of approximately 275 mm. There are no complete 

 mouth-borders and no lappets or other evidence of microconchs. 

 Inner whorls are evolute, with a depressed whorl section and rounded 



