Megapodius

MEGAPODIUS View in CoL INDET SP.

Material: Hopoate: NISP = 4, MNI = 1. Falevai: NISP = 2. Ofu: Of1.05.12.07, ungual phal; NISP = 1. Vuna: NISP = 8, MNI = 2.

Remarks: These specimens are either juvenile, undiagnostic elements or too fragmentary for identification to species level.

MEGAPODE GENUS & SPECIES INDET . LARGE SP.

Material: Ofu: Of1.05.22.07, dL hum ( SW = 7.85 mm, D W = 1 8.8 m m); N I S P = 1, M N I = 1. Vu n a: Pa1.04.18.10a, four frags L cor; NISP = 1, MNI = 1.

Remarks: These specimens are bigger than specimens for M. alimentum and about the same size as specimens of Macrocephalon maleo Müller, 1846 or that expected of M. molistructor , for which no humerus is known. On the distal humerus, the fossa brachialis is deep, and the origin of m. extensor carpi radialis has two scars aligned level with the most proximal point of condylus dorsalis. The pars dorsalis is round, elevated off the surface and protuberant craniodorsally on the dorsal margin, but extends less dorsally than the epicondylus dorsalis, from which it is separated by a shallow notch, as seen in cranial aspect. The pars ventralis is elongated and lies ventrad and extends slightly distal to the former. In Macrocephalon maleo AMNH 12013, the pars dorsalis origin of m. extensor carpi radialis is prominent dorsally of the shaft, but lies distal to the pars ventralis and is more prominent than the epicondylus dorsalis. Also, the shaft is more robust ( SW = 9.3 mm, DW = 18.5 mm), together, precluding referral of the Tongan bone to this genus and species. The distal humerus of Mwalau from Vanuatu is not known; therefore, comparison to the Tongan sample cannot be made, but it was a bigger bird than all extant megapodes ( Worthy et al., 2015). In M. reinwardt ( ANWC 22869) and M. alimentum specimens above, the pars dorsalis of the origin of m. extensor carpi radialis is also located immediately and entirely distal to the pars ventralis and on the dorsal facies and forms a low processus supracondylaris dorsalis that projects further dorsally than the epicondylus dorsalis. Therefore, Of1.05.22.07 cannot be referred to Megapodius . Steadman referred numerous bones to M. molistructor but stated that they ‘were somewhat aberrant among Megapodius and may, with further study, warrant its own genus’ ( Steadman, 2006a: 292). The coracoid fragments represent a species about as large as the humerus, but little more can be said. Steadman (2006a: 292) noted that M. molistructor was scarce in the Ha'apai Group relative to M. alimentum , which accords with our observations of the sites reported herein. Therefore, the bones listed here probably belong to Steadman's (2006a) ‘ M. molistructor ’, but assessing their relationship among megapodes is outside the scope of this report.