. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. ANNALS OF THE SOUTH AFRICAN MUSEUM. ength Fig. 15. Length/height scattergram (in mm) of specimens of Brachycythere. Solid line and circles = type specimens from the middle and late Cretaceous of Africa and adjacent areas; dashed line and triangles = specimens of B. sapucariensis reported in the literature; maltese cross = specimens reported as B. aff. sapucariensis by Bate & Bayliss (1969). Key to species: 1 = B. ekpo, 2 = B. rotunda, 3 = Brachycythere IR E10, 4 = Brachycythere IR C28, 5 — B. ang
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. ANNALS OF THE SOUTH AFRICAN MUSEUM. ength Fig. 15. Length/height scattergram (in mm) of specimens of Brachycythere. Solid line and circles = type specimens from the middle and late Cretaceous of Africa and adjacent areas; dashed line and triangles = specimens of B. sapucariensis reported in the literature; maltese cross = specimens reported as B. aff. sapucariensis by Bate & Bayliss (1969). Key to species: 1 = B. ekpo, 2 = B. rotunda, 3 = Brachycythere IR E10, 4 = Brachycythere IR C28, 5 — B. angulata, 6 = Brachycythere IR J10, 7 = B. sapucariensis, 8 = 5. armata, 9 — B. kulatturensis, 10 = Brachycythere IR J9, 11 = B. oguni, 12 = B. dumoni, 13 = Brachy- cythere IR E5, 14 = B. ledaformis (as reported by Masoli (1966)), 15 — B. agulhasensis, 16 = Brachycythere IR H34, 17 = B. pondolandensis, 18 = B. sicarius, 19 = B. longicaudata. morphotypes on the grounds of lateral outline, such subdividsion has been found impractical because the bulk of the populations would then fall into intermediate categories. In terms of lateral outline (regardless of valve size) this poses problems in discriminating B. longicaudata from certain other species, notably B. sapucariensis. On a length/height scattergram of holotypic (and neotypic) specimens of Brachycythere from Africa and adjacent areas, the types of B. longicaudata and B. sapucariensis are widely separated, and in lateral outline are clearly differentiated (Fig. 17). This distinction is also seen in other points of morphological difference: curvature of AM, shape of VM, shape and spinosity of posteroventral area. The two types are Santonian and Coniacian age, respec- tively. However, several other workers have reported Krommelbein's Brazilian species from localities in west and north Africa, and if representatives of these materials are compared in shape (but not size) to the general population of B. longicaudata, the disti
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