AMMONITES AND NAUTE^OIDS OF WADI HAJAR 



Spiticeras (Spiticeras) spitiense (Blanford, 1863) 



PI. 17, fig. 1 



1863 Ammonites spitiensis Blanford: 131, pi. 2, fig. 4. 



1903 Holcosiephamis (Spiticeras) spitiensis (Blanford); Uhlig; 



89, pi. 8, figs 1-3. 

 71922 Spiticeras cf. spitiense (Blanford); Djanelidze: 130, pi. 11, 



figs 1,2. 

 1992 Spiticeras (Spiticeras) spitiense (Blanford); Howarth: 620, 



pi. 5, figs 1, 4. 



Material. CA596 from bed 31 of the Mintaq Member, Mintaq 

 Salt Dome. 



Description. The outer whorl is 105 mm in diameter and is 

 probably part of a body-chamber because suture-lines appear to be 

 absent; it is moderately involute, with broad rounded whorls, though 

 slightly trigonal in section and very bluntly angled on the venter, and 

 has the following measurements: at 103.0 mm: 36.3 (0.35), 35.8 

 (0.35), 39. 1 (0.38). There are 9 or 10 large umbilical tubercles on the 

 last half whorl; three or four ribs diverge from each tubercle, then 

 swing forwards and form chevrons across the bluntly angled venter. 



Remarks. This is a typical Spiticeras with broad rounded whorls, 

 large umbilical tubercles and moderately strong ribbing. It is very 

 similar to the specimen figured by Howarth ( 1992) from Kurdistan, 

 where its age was shown to be Boissieri Zone, upper Berriasian. 



Occurrence. Mintaq Member, Hajar Formation, Mintaq Salt 

 Dome; Occitanica Zone, Berriasian. 



Spiticeras (Spiticeras) subspitiense (Uhlig, 1903) 



PI. 16, fig. 4 



1903 Holcostephanus (Spiticeras) subspitiense Uhlig: 95, pi. 9, 

 fig. 4. 



Material. Two specimens, CA597 from bed 34 and CA598 from 

 bed 69 of the Mintaq Member, Mintaq Salt Dome. 



Description. CA597 is half a whorl of incomplete body-cham- 

 ber, 82 mm diameter; CA598 is 78 mm diameter and probably 

 wholly septate. The involute whorls have a compressed, trigonal 

 whorl section that converges towards a narrowly rounded venter; 

 about 8 large umbilical tubercles per half whorl are elongated 

 radially and pass into poorly defined ribs in the middle of the whorl 

 side; these then divide into many smaller better defined ribs on the 

 outer part of the whorl and pass across the venter angled forwards. 

 One poorly developed constriction occurs on CA597. 



Measurements 









D 



Wh 



Wb 



U 



CA597 82.5 



30.0 (0.36) 



19.0(0.23) 



29.6(0.36) 



CA598 77.0 



29.5 (0.38) 



21.6(0.28) 



25.3(0.33) 



compression, few are as compressed or as smooth as in subspitiense, 

 and the Yemen specimens at least are tending towards the even more 

 compressed and smoother subgenus Negreliceras. 



Occurrence. Mintaq Member, Hajar Formation, Mintaq Salt 

 Dome; Occitanica Zone, Berriasian. 



Spiticeras (Spiticeras) indicum (Uhlig, 1903) PI. 17, fig. 3 



1903 Holcostephanus (Spiticeras) indicum Uhlig: 124, pi. 10, 

 fig. 3. 



Material. CA599 and CA600 from bed 3 1 of the Mintaq Mem- 

 ber, Mintaq Salt Dome. 



Description. CA599 is a well-preserved, uncrushed ammonite, 

 in which the end of the phragmocone is clearly seen at 70 mm 

 diameter, and is followed by a complete body-chamber, 320° long 

 and 1 20 mm diameter at the mouth-border of which only a small part 

 is preserved. CA600 is a fragment of a body-chamber, about one- 

 third of a whorl long and 1 15 mm diameter at its larger end. The 

 whorls are moderately involute, and have an evenly rounded cross- 

 section. There are about 12 small, radially elongated, umbilical 

 tubercles per half whorl at 90-1 10 mm diameter; four or five radial 

 ribs issue from each tubercle and curve gently forwards across the 

 side of the whorl and meet at an obtuse angle in the middle of the 

 venter. 



Measurements 









D 



Wh 



Wb 



U 



CA599 111.5 



38.2 (0.34) 



— 



41.4(0.37) 



CA599 70.0 



27.0 (0.39) 



29.8 (0.43) 



— 



CA600 — 



35.7 



34.0 



— 



Remarks. The whorls are trigonal in cross-section and more 

 compressed than in S. (S.) spitiense and the ribbing is weaker on the 

 middle of the side of the whorls and finer on the venter. Although S. 

 (S.) spitiense shows some variation in whorls shape and amount of 



Remarks. These specimens have finer ribs and smaller umbilical 

 tubercles than5. (S.) spitiense or subspitiense. The ribs are also more 

 confinuous and persistent, showing no tendency to fade in the 

 middle of the whorl side or near the umbilical tubercles as in most 

 species of Spiticeras. S. (S.) guttatus (Blanford), S. (S.) planus 

 (Uhlig) and 5. (S.) obliquelobatus (Uhlig). described by Uhlig 

 (1903) from the Spiti Shales, are similar, but all have larger umbili- 

 cal tubercles, coarser ribs or more compressed whorls. Spiticeras 

 (S.) multiforme Djanelidze (1922: 143), from the Berriasian of SE 

 France, is possibly more similar to the Yemen specimens, but it also 

 has larger umbilical tubercles. 



Occurrence. Mintaq Member, Hajar Formation. Mintaq Salt 

 Dome; Occitanica Zone. Berriasian. 



Spiticeras (Spiticeras) pricei sp. no v. 



PI. 16, fig. 6; PI. 17, figs 2, 4, 6; PI. 18, fig 1. 2 



Derivation of name. After Dr Ashley Price, BP Exploration Co., 

 who first located the horizon at Mintaq in which it occurs. 



Holotype. CA666 from bed 75 of the Mintaq Member, Mintaq 

 Salt Dome. 



Paratypes. Seven paratypes are designated: CA619. 621. 626 



PLATE 17 



Fig. 1 Spiticeras (Spiticeras) spitiense (Blanford), bed 31. Mintaq Member (fauna 13), Mintaq Salt Dome, la, lb, CA596, '.'body-chamber. 



Figs 2, 4, 6 Spiticeras pricei sp. nov., paratypes, Mintaq Member (fauna 13), Mintaq Salt Dome. 2a, 2b, CA626 from bed 60 (the asteri.sk marks the 



probable end of the phragmocone); 4a, 4b, CA621 from bed 60; 6a, 6b, CA663 from bed 69. 

 Fig. 3 Spiticeras (Spiticeras) indicum (Uhlig), bed 31. Mintaq Member (fauna 13), Mintaq Salt Dome. 3a, 3b, CA599. xO.78. 

 Fig. 5 Spiticeras (Spiticeras) gregoryi (Spath), microbialite boulders, Arus Member (fauna 9), we.sl cliff, Wadi Arus. 5a, 5b, CA773. 



