Macropus (Notamacropus), 1985

Piper, Katarzyna J., 2016, The Macropodidae (Marsupialia) of the early Pleistocene Nelson Bay Local Fauna, Victoria, Australia, Memoirs of Museum Victoria 74, pp. 233-253 : 234-237

Macropus (Notamacropus) spp. Dawson and Flannery, 1985

Referred material. NMV P173678, right I2; NMV P200669, left I2; NMV P215807, left I2; NMV P215808, left I2; NMV P215809, left I2; NMV P215814, I2; NMV P200643, worn left I3; NMV P215813, left I3; NMV P215815, worn right I3; NMV P216046, unerupted left I3; NMV P173656, right maxillary fragment containing partial dP3 and M1?; NMV P187189, left dP3?; NMV P215783, metaloph left dP3?; NMV P200626, worn left M1?; NMV P187185, left M3 or M4; NMV P216887, left M3 or M4; NMV P200675, trigonid left m2?; NMV P200606, trigonid left m3?; NMV P215821, left m3?; NMV P173655, right i1; NMV P216895, partial left i1.

Remarks. A few isolated and partial molars are tentatively referred to Macropus (Notamacropus) spp. on the basis of being high crowned; possessing strong midlinks; having a vertical hypolophid, which is not markedly rounded or convex posteriorly and lacks any ornamentation or a posterior cingulid; possessing a strong preparacrista; and lacking a forelink on upper molars ( fig. 3 ) ( Dawson and Flannery, 1985).

The lower molars differ from Baringa nelsonensis in being relatively broader, with a broader, shorter, more upturned anterior cingulum and stronger premetacristid ( fig. 3A ). They differ from Thylogale billardierii in being much larger and higher crowned, and possessing a broader, shorter more upturned anterior cingulum. They are most similar overall to Macropus (Notamacropus) rufogriseus in size and in the morphology of the anterior cingulum.

Two small, unworn i1s may be referable to Macropus (Notamacropus) as they are lanceolate in shape, long relative to depth, bear sharp dorsal and ventral enamel flanges and lack any thick ventrolingual enamel ( fig. 3B ) ( Dawson and Flannery, 1985). They are closest in size to Macropus (Notamacropus) parryi (max. depth, 5.4 mm and 5.3 mm, respectively).

Two upper molars ( NMV P187185, P216887) are similar in size and morphology to Macropus (Notamacropus) eugenii , but also show some similarities to Petrogale ( fig. 3C ). Four other smaller upper molar specimens ( NMV P173656, P187189, P200626, P215783) all possibly represent anterior and deciduous molars from the same species ( fig. 3D ). They are smaller and relatively narrower, and have a much longer, narrower anterior cingulum than Thylogale billardierii , but are quite close in both size and morphology to Macropus (Notamacropus) parryi .

A few isolated upper incisors are also referable to this genus. They are similar in size and morphology to Macropus (Notamacropus) rufogriseus and Macropus (Notamacropus) parma .

Many of the features used here to identify these specimens as Macropus are also present in species of Petrogale , Onychogalea and Prionotemnus , and to add further difficulties there are no single characters that can be used to distinguish Macropus from other macropodines ( Dawson and Flannery, 1985). At least two species are present in the Nelson Bay LF; however, owing to the fragmentary nature of the specimens, and a lack of association with premolars or incisors, identification to species level is extremely difficult and identification to generic level is questionable.

Figures

Figure 3. Macropus (Notamacropus) spp.: a, NMV P215821, left m3?, occlusal view; b, NMV P173655, right i1, labial view; c, NMV P187185, left M, occlusal view; d, NMV P173656, right dP3–M1?, occlusal view. Scale bar = 5 mm.