. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. AGRIOTHERIUM FROM LANGEBAANWEG, SOUTH AFRICA 83 slightly less high-crowned than the protoconid ( Crusafont & Kurten 1976, fig. 13). Much the same applies in the case of /. vireti and /. arctoides, except that in these species the metaconid and entoconid are of comparable size (Crusafont & Kurten 1976, fig. 2; Tobien 1955, fig. 3). In /. atticus the metaconid is much less prominent than the protoconid, but is still of similar size to the entoconid (Helbing 1932, fig. 3). In the smallest of
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. AGRIOTHERIUM FROM LANGEBAANWEG, SOUTH AFRICA 83 slightly less high-crowned than the protoconid ( Crusafont & Kurten 1976, fig. 13). Much the same applies in the case of /. vireti and /. arctoides, except that in these species the metaconid and entoconid are of comparable size (Crusafont & Kurten 1976, fig. 2; Tobien 1955, fig. 3). In /. atticus the metaconid is much less prominent than the protoconid, but is still of similar size to the entoconid (Helbing 1932, fig. 3). In the smallest of the A. africanum Mi's (L50006) what is interpreted as a vestigial metaconid is still present. It is completely overshadowed by the proto- conid, and, unlike its counterpart in /. atticus, is smaller than the entoconid. The metaconid is absent in all other Mi's from Langebaanweg, and, apparently also from all other recorded Agriotherium Mx's. The progressive reduction and eventual loss of the Mx metaconid in the Ursavus-Indarctos-Agriotherium lineage is illustrated in Figure Fig. 36. Mx's. A. Ursavus primaevus (after Crusafont & Kurten 1976, fig. 14). B. Indarctos arctoides (after Tobien 1955, fig. 3). C. Indarctos atticus (after Helbing 1932, fig. 3). D. Lange- baanweg Agriotherium (D1-L50006; D2-L50004; D3-L50446). All are lingual views except C, which is a buccal view with the buccal talonid cusps omitted, e—entoconid; m—metaconid; p—protoconid. If the largest of the posterolingual Mx cusps in Agriotherium is indeed the entoconid ( a talonid cusp), rather than the metaconid ( a trigonid cusp), this would account for Tobien's (1955: 14) observation that the 'Metaconid' of Agriotherium is 'niedriger und starker zuriickgeschoben', while in Indarctos it is. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble t
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
