STRATIGRAPHY AND TRILOBITE FAUNAS FROM THE CAMBRIAN BURJ FORMATION 



143 



through the palpebral lobes it is <40% of cranidial width (Fig. 28b). 

 No occipital spine or node. Frontal area relatively long, nearly 25% 

 of cranidial length. Surface smooth, but the internal mould shows 

 tiny pits (= granules on the parietal surface of the cranidium) and 

 caeca on the preglabellar field. 



Among Kingaspidoides without an occipital spine, K. obliquocu- 

 latus differs from K. neglectus Geyer (1990b: 120) in having a 

 shorter and narrower glabella, and from K. borjensis Geyer (1990b: 

 122) in having a shorter palpebral lobe which does not extend back 

 to the level of SO. 



Horizon. Burj Formation. Ghor-es-Safi. K. obliquoculatus was 

 originally described from theAsrir Formation (Jiupeolenus Zone) of 

 the Fouggara section in the Anti-Atlas Mountains, Morocco. 



Family PALAEOLENIDAE Hupe, 1953 



Discussion. The Palaeolenidae were discussed and briefly char- 

 acterised by Geyer (1990b: 67). The glabella is well defined and 

 tends to be clavate and typically shows four pairs of glabellar 

 furrows; the posterior pair (SI) curve slightly inwards and back- 

 wards, S2 and S3 are nearly transverse, short and not connected 

 across the glabella, and S4 is short and slightly oblique inwards and 

 forwards. In Palaeolemis lantenoisi Mansuy. 1912, the glabella is 

 almost parallel-sided but in P. douvillei Mansuy, 1912, the type of 

 the genus, the glabella is slightly clavate: in both those species the 

 preocular sections of the facial suture are approximately parallel. In 

 P. deprati Mansuy. 1912, the type species of Megapalaeolenus 

 Chang, 1966, the glabella is clavate and the preocular sutures 

 diverge forwards. It is doubtful whether Megapalaeolenus should be 

 maintained as an independent genus. 



Genus PALAEOLENUS Mansuy, 1912 



DISCUSSION. The species described below was originally assigned 

 to the genus Schistocephalus Chernysheva, 1956, which has been 

 regarded as a member of the Family Paradoxididae. The distance 

 from the anterior end of the palpebral lobe to the glabella, connected 

 by an eye-ridge, and the presence of a parafrontal band (Fig. 29a), 

 are features of various genera commonly referred to the superfamily 

 Ellipsocephaloidea (Geyer 1990b). The type species of Schisto- 

 cephalus, S. enigmaticus Chernysheva (1956: pi. 30, figs 1, 3), has a 

 parallel-sided glabella on which the glabellar furrows SI to S3 are 

 arched backwards and joined strongly across the mid-line; S4 lies 

 relatively close to S3 and is very short The anterior part of the 

 glabellar appears transversely oval. Other species of Schistocephalus 

 have been described which show rather diverse glabellar morphol- 

 ogy (Chernysheva 1971: pis 6, 7). Most of them have a slightly 

 clavate glabellar with a semi-circular frontal lobe; some of them, 

 such as S. juvenis Chernysheva, 1956(Sdzuy 1995: pi. 1. fig. 8) and 

 S. amzassiensis Fedjanina (in Chernysheva 1971: pi. 6, figs 8-13). 

 share with S. enigmaticus the strongly transglabellar furrows S2 and 

 S3. See also 5. ex gr. juvenis well figured in Egorova et al. (1976: pis 

 32-34). In some other early species such as 5. antiquus Chernysheva, 

 1956, andS. tchernyshevae Bognibova (in Chernysheva 1971) these 

 furrows do not join across the glabella. The latter forms are closer in 

 this feature toPalaeolenus (especially species that have been referred 

 to Megapalaeolenus) and it seems appropriate to transfer them to 

 that genus rather than extend Schistocephalus unduly. Chu (1962) 

 suggested that Palaeolenus is ancestral to Schistocephalus. 



Ferralsia Cobbold (1935) is very similar to Palaeolenus, but 



Geyer & Elicki (1995: 112). who reviewed Ferralsia. maintained 

 that it could be distinguished from Palaeolenus by its shorter and 

 more regularly spaced glabellar furrows; in at least some species of 

 Palaeolenus S3 and S4 are closer together than SI and S2. Further- 

 more, Ferralsia tends to have a longer preglabellar field and narrower 

 interocular fixigenae. However, in view of the variation shown by 

 species of Palaeolemis and Schistocephalus, these features, even if 

 they are considered to be of generic value, may be difficult to apply. 

 It is possible that the genus Gigoutella Hupe, 1953, would be an 

 appropriate reference for some of those taxa with discontinuous 

 glabellar furrows, but regrettably the genus is known only from a 

 single schematic line-drawing (which is misleading according to t 

 Geyer & Elicki 1995: 112). As attempts to examine the original 

 material have been unsuccessful, the nature and relationships of the 

 only described species, G. atlasensis Hupe (1953), remain to be 

 elucidated, but it may prove to be a senior synonym of Megapalae- 

 olenus (and, following Sdzuy (1995), Schistocephalus if a broad 

 view is taken of that genus), or a junior synonym of Ferralsia. 



Palaeolenus antiquus (Chernysheva, 1956) Figs 29-38 



1956 Schistocephalus antiquus Chernysheva: 150, pi. 30, fig. 6 



[cranidium figured, compared with S. enigmaticus]. 

 1976 Schistocephalus antiquus Tchernysheva [sic]; Egorova et 



al:. 74, pi. 23, figs 1 1-14. pi. 25, figs 1,2, pi. 28, fig. 1 



[figures of several cranidia]. 

 1995 Schistocephalus antiquus Chernysheva; Sdzuy: pi. 1, fig. 9 



[new figure of holotype]. 



New MATERIAL. Sixteen cranidia (mostly fragmentary), two 

 librigenae and three small pygidia, all from a calcarenite bed (Fig. 6) 

 in a culvert, 0.8 km N of Wadi Zarqa Ma'in (BM H26214-30). 



Description. Glabella (including occipital ring, LO) clavate, oc- 

 cupies 85% of cranidial length; forward of L2 widens to a maximum 

 opposite S4, where it is about 120% of the width of LI. Glabellar 

 lobes LI to L4 become progressively shorter (exsag.); the frontal 

 lobe is well rounded anteriorly. LO without node. S 1 slightly curved 

 inwards and backwards, with a tendancy to bifurcate medially: S2 

 approximately transverse but each furrow forms a slight convex 

 curve anteriorly; S3 similar to S2 but extends inwards and slightly 

 forwards; S4 shorter than S3, curved or more anteriorly directed. 

 Anterior border has terrace-lines parallel to margin and is a little 

 longer sagittally than preglabellar field. Preocular section of facial 

 suture diverges forward at about 30° to sagittal line. Palpebral lobe 

 one-third of cephalic length, continuous with eye-ridge which reaches 

 glabella opposite S4 and extends forward into a narrow parafrontal 

 band, seen on some specimens (Figs 29a, 34). Interocular area of 

 fixigena about two-thirds of glabellar width at SI. Postocularareaof 

 fixigena not quite as wide as LO. Exterior surface granulose, most 

 coarsely so on the median part of the glabella and the interocular 

 fixigena, more finely on the preocular fixigena. Internal mould 

 almost smooth, very finely pitted, indicating very fine granulation 

 on the parietal surface of the exoskeleton. 



Librigena narrow, the border occupying nearly half the total 

 width. Genal spine very short (Fig. 36). 



Pygidium small, with wide short axis having one distinct and one 

 faint axial ring. Pleural field very small with one pleural furrow and 

 two faint interpleural grooves (Fig. 33). 



Discussion. The specimens from Wadi Zarqa Ma'in agreeclosely 

 with the holotype and also the specimens figured by Egorova et al. 

 ( 1976), except that the interocular fixigena is a little wider in some 

 of the Jordanian specimens; the glabella widens forward less than in 

 the holotype (Sdzuy 1995: pi. 1, fig- 9), but more than some of the 



