Eurites Kusina, 1973

Korn, Dieter, Bockwinkel, Jürgen, Ebbighausen, Volker & Klug, Christian, 2003, Palaeobiogeographic and evolutionary meaning of an early Late Tournaisian ammonoid fauna from the Tafilalt of Morocco, Acta Palaeontologica Polonica 48 (1), pp. 71-92 : 83

publication ID	https://doi.org/ 10.5281/zenodo.13272527
persistent identifier	https://treatment.plazi.org/id/03BE87DE-5A7C-FFCB-FFB2-FE5C735FFA97
treatment provided by	Felipe
scientific name	Eurites Kusina, 1973
status

Treatment

Eurites Kusina, 1973 View in CoL

Type species.– Eurites latus Kusina, 1973 .

Eurites bouhamedensis sp. nov.

Figs. 18H, I View Fig , 19 View Fig , 20 View Fig .

Derivation of name: After Ksar Bouhamed, where the fauna was collected.

Holotype: Specimen MB.C.3947 (coll. Klug), Fig. 18H View Fig .

Type locality and horizon: Taouz, Jebel Ouaoufilal, locality B east of Ksar Bouhamed (Tafilalt, Morocco); Oued Znaïgui Formation, early Late Tournaisian.

Material.—12specimensbetween5and15mmconchdiameter.

Diagnosis.— Eurites with pachyconic conch between 8 mm and 15 mm diameter (ww/dm 0.80). Umbilicus narrow to moderately wide (uw/dm 0.25 to 0.35), umbilical margin angular, umbilical wall steep. Steinkern with three or four constrictions. Suture line with moderately deep, V−shaped external lobe, low median saddle, and V−shaped symmetrical adventive lobe.

Description.—Specimens of all growth stages share a similar conch geometry ( Fig. 19 View Fig ). The holotype is among the more globose specimens, with a broad venter and a distinct umbilical edge. Smaller specimens show a less pronounced umbilical margin.

Steinkerns possess three or four prominent constrictions per volution, which begin immediately outside of the umbilical margin and are almost linear across flanks and venter.

The suture line of the holotype MB.C.3947 shows a moderately deep external lobe and a much deeper, V−shaped and almost perfectly symmetrical adventive lobe. The ventrolateral saddle is wide, broadly rounded, and nearly symmetrical ( Fig. 20 View Fig ) .

Dimensions.—(in mm). Comparisons.—Some species belonging to Eurites have conchs similar to E. bouhamedensis sp. nov.: E. latus Kusina, 1973 has a much narrower and deeper external lobe. E. saginatus ( Gordon, 1957) (whorl width/ conch diameter 0.90) is more globose. E. ellipsoidalis ( Crick, 1899) and E. obesus ( Foord, 1903) (ww/dm less than 0.60) are more 1 10 100 conch diameter discoidal and have narrower umbilici (one fifth of the diameter). E. sphaeroidalis ( McCoy, 1844) , E. corpulentus ( Crick, 1899) , E. latumbilicatus ( Kullmann, 1961) , and E.? browni McCoy, 1844 do not have constrictions. E. corpulentissimus ( Schindewolf, 1951) is similar in its conch geometry, but has a deeper external lobe and an asymmetrical adventive lobe (in contrast to the moderately deep external lobe and symmetrical adventive lobe in E. bouhamedensis sp. nov.). E. inflatus ( Delépine, 1940) is more narrowly umbilicate (one fifth of the diameter) than the new species.