Pseudaptenodytes macraei Simpson, 1970

Park, Travis & Fitzgerald, Erich M. G., 2012, A review of Australian fossil penguins (Aves: Sphenisciformes), Memoirs of Museum Victoria 69, pp. 309-325 : 319-320

Pseudaptenodytes macraei Simpson, 1970

Holotype. Partial left humerus ( NMV P26668 ). ( Fig. 11; Table 2).

Type locality. Spring Creek near Minhamite, 41 km southeast of Hamilton , Victoria (37°58'S, 142°23'E) .

Horizon and age. The holotype is derived from the Goodwood Formation, a green-grey marly fine sand with abundant pebbles ( Gill, 1964:332). The macroinvertebrate assemblage is similar to that of the Upper Miocene–Lower Pliocene Black Rock Sandstone ( Gill, 1964; Simpson, 1970), and the Goodwood Formation is possibly laterally equivalent to the Upper Miocene–Lower Pliocene Grange Burn Formation ( Fitzgerald, 2004).

Referred material. A partial right carpometacarpus ( NMV P27055) and a partial left carpometacarpus ( NMV P27056) were tentatively referred to this species ( Simpson, 1970) ( Fig. 15 ; Table 2). Both specimens were derived from the Upper Miocene–Lower Pliocene Black Rock Sandstone at Beaumaris.

Diagnosis. Simpson (1970) noted the very close similarity of Pseudaptenodytes macraei to Aptenodytes patagonicus , both in terms of size and the features of the proximal end of the humerus. Nevertheless, P. macraei differs from Aptenodytes by having a humerus with: a more sigmoid shaft; a smaller volume of the fossa pneumotricipitalis; a distinctly oval opening of the internal division of the fossa pneumotricipitalis; and a rounded cranial margin lacking a distinct ‘preaxial angle’ ( Acosta Hospitaleche et al., 2008: Fig. 5 , char. 11). It further differs from A. forsteri by lacking the pit for ligament insertion on the proximal surface adjacent to the head (Ksepka et al., 2006: Fig. 8 ). In A. patagonicus this feature is variable (Ksepka et al., 2006).

Remarks. Despite the similarities of the type specimen to Aptenodytes patagonicus , Pseudaptenodytes macraei is not ancestral to it or any of the modern species ( Simpson, 1970: 20). Although similar, the autapomorphies of NMV P26668 preclude this specimen from referral to Aptenodytes or any extant genera. We consider P. macraei to be a distinct taxon established on the basis of a diagnostic type specimen.

? Pseudaptenodytes minor Simpson, 1970

Holotype. Partial right humerus ( NMV P26669 ). ( Fig. 14 ; Table 2).

Type locality. East of Rickett’s Point on the western shore of Beaumaris Bay, northeast shore of Port Phillip Bay , Victoria (37°59'S, 145°03'E) .

Horizon and age. Black Rock Sandstone, which consists of a basal layer of phosphatic and ferruginous intraclasts overlain by calcareous sandstone ( Dickinson and Wallace, 2009). Planktonic foram and molluscan biostratigraphy indicate a Late Miocene–Early Pliocene age range, which is corroborated by Sr dates of 5.0–6.2 Ma ( Dickinson and Wallace, 2009).

Referred material. Distal end of right humerus ( NMV P26677), proximal end of left humerus, ( NMV P26671), proximal end of left humerus ( NMV P26676), right humerus ( NMV P26670), right humerus ( NMV P27057), partial right carpometacarpus ( NMV P27058), right carpometacarpus ( NMV P26903) ( Fig. 13 ; Table 2). All referred material was collected from the Upper Miocene–Lower Pliocene Black Rock Sandstone at Beaumaris. Diagnosis. Differs from Pseudaptenodytes macraei by having: a more slender and less sigmoid shaft; and a less expanded distal section ( Simpson, 1970). It also differs by having a distinct angle on the cranial margin, although this angulation is still less than that of any modern penguin ( Simpson, 1970).

Remarks. Simpson (1970) notes the similarities between? Pseudaptenodytes minor and Paraptenodytes robustus yet the holotype of? P. minor is too incomplete to permit meaningful comparisons. The lack of diagnostic morphology in the type specimen of? P. minor has resulted in Ksepka and Clarke (2010) referring this taxon to Sphenisciformes indet. More completely preserved material is required to confirm or reject the placement of this species in Pseudaptenodytes . The additional material referred by Simpson (1970) to? P. minor displays little overlap in morphology with the holotype ( NMV P26669). Furthermore, it is only on the basis of the referred material that the holotype was designated a species of Pseudaptenodytes . We therefore recommend restricting the concept of? P. minor to the holotype. All referred material should be considered Sphenisciformes indet. pending further study.

Figures

Figure 5. Pachydyptes simpsoni paratype, SAM P14158: proximal end of right radius in (A) ventral view and (C) dorsal view; partial right humerus in (B) ventral and (D) dorsal views.

Figure 8. Sphenisciformes indet. partial right humerus, SAM P10863: A, dorsal view; B, ventral view.

Figure 13. Sphenisciformes from the Upper Miocene–Lower Pliocene Black Rock Sandstone, Victoria. A–J and M–P, specimens referred to?Pseudaptenodytes minor: partial left humerus, NMV P 26671, in (A) dorsal and (B) ventral views; partial left humerus, NMV P26676, in (C) dorsal and (D) ventral views; partial right humerus, NMV P26677, in (E) dorsal and (F) ventral views; partial right humerus, NMV P26670, in (G) dorsal and (H) ventral views; partial right humerus, NMV P27057, in (I) dorsal and (J) ventral views; partial right carpometacarpus, NMV P27058, in (M) dorsal and (N) ventral views; partial right carpometacarpus, NMV P26903, in (O) dorsal and (P) ventral views. Sphenisciformes indet. partial left humerus, NMV P27059: K, dorsal view; L, ventral view.

Figure 14.?Pseudaptenodytes minor holotype partial right humerus, NMV P26669: A, dorsal view; B, ventral view.

Figure 15. Specimens referred to Pseudaptenodytes macraei: partial right carpometacarpus, NMV P27055, in (A) dorsal and (B) ventral views; partial left carpometacarpus, NMV P27056, in (C) ventral and (D) dorsal views.