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200 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY
The range of body sizes in the megapodes varies from the extinct
Progura gallinacea De Vis (1888) of Australia, which
reached the size of a turkey {Meleagris), to Megapodius laperouse
of Micronesia, the smallest described species (28-30 cm).
Steadman (1993a) reported an extinct, as yet undescribed species
of Megapodius from the late Quaternary of 'Eua, Tonga,
which was smaller than any other known megapode. The earliest
known fossil occurrence of the Megapodiidae is from the
Pliocene (Boles and Mackness, 1994); most records are from
the Pleistocene. Because of its age and diminutive size, a recently
identified megapode from late Oligocene deposits of
central Australia, outside the current distribution of this family,
is of considerable interest.
FOSSIL RECORD OF MEGAPODES
Mourer-Chauvire (1982) initially indicated the presence of
the Megapodiidae in the Eocene-Oligocene deposits of Quercy,
France. Later she regarded these as belonging to a more primitive
family of galliforms, the Quercymegapodiidae (Mourer-
Chauvire, 1992), consisting of the single genus Quercymegapodius,
which she created for Palaeocryptonyx depereti Gaillard
(1908), and a new species, Q. brodkorbi Mourer-Chauvire
(1992). This family was interpreted as being the sister group of
all the living Galliformes. Excluding the Quercymegapodiidae,
there are no known occurrences of fossil megapodes outside
Australia and the islands of the southwest Pacific.
The Pleistocene record of megapodes is dominated by the
fossil genus Progura. Progura gallinacea was originally described
by De Vis (1888) as a large pigeon. Van Tets (1974)
recognized that the specimens belonged to a megapode larger
than any living species. Additional material identified by De
Vis as pigeons, as well as material he identified as storks or as
bustards, also was included in this taxon (van Tets, 1974; van
Tets and Rich, 1990). Specimens of a smaller but related form
were described as P. naracoortensis by van Tets (1974), to
which were referred fossils that previously had been attributed
to Alectura lathami (Lydekker, 1891; Longman, 1945). It was
later suggested (van Tets, 1984) that the two taxa of Progura
actually represented a single, sexually dimorphic species. The
only other Australian species in the fossil record is Leipoa
ocellata, which has been recovered from late Pleistocene deposits
in South Australia (van Tets, 1974). The only Tertiary
records come from the Pliocene of Australia. De Vis (1889) described
the fossil megapode Chosornis praeteritus from Chinchilla,
Queensland, which van Tets (1974) later placed in the
synonymy of the Pleistocene species Progura gallinacea.
Boles and Mackness (1994) reported on the presence of P. cf.
naracoortensis at Bluff Downs, Queensland.
A variety of fossil species of Megapodius, mostly extinct
forms, are known from South Pacific islands from New Caledonia
(Balouet and Olson, 1989) eastward into Polynesia
(Steadman, 1989, 1993a, 1993b, 1995; see also Jones et al.,
1995). Most of these sites are of Holocene age, and most or all
of the extinctions were anthropogenic.
The enigmatic Sylviomis neocaledoniae of New Caledonia
was first described as a ratite (Poplin, 1980) but later was considered
to be a large, flightless megapode (Poplin and Mourer-
Chauvire, 1985). Balouet and Olson (1989) and C. Mourer-
Chauvire (pers. comm., 1996) believe that that Sylviomis belongs
to the Galliformes but is best placed in its own family.
METHODS.—Measurements mostly follow those of Steadman
(1980) and were made with digital calipers and rounded to
the nearest 0.1 mm. Osteological nomenclature follows
Baumel and Witmer (1993); taxonomic nomenclature for the
Megapodiidae follows Jones et al. (1995). Comparisons were
made with representatives of all extant genera of megapodes
{Macrocephalon maleo, Eulipoa wallacii, Alectura lathami,
Leipoa ocellata, Talegalla jobiensis, T. fuscirostris, Aepypodius
arfakianus, A. bruijni, Megapodius reinwardt, M. freycinet,
M. eremita, M. pritchardi, M. cumingii, M. nicobarensis) as
well as with Progura gallinacea.
ACKNOWLEDGMENTS.—We thank T. Rich (Museum of Victoria)
and P. Vickers-Rich (Monash University) for permitting us
to work on this fossil; T. Rich for supplying information from his
field notes on the discovery of this specimen; D. Steadman for
discussion of this fossil and of his work with megapodes; S. Olson,
D. Steadman, and C. Mourer-Chauvire for valuable criticisms
of the manuscript; T. Wickey and C. Bento (Australian
Museum) for taking the photographs; R. Schodde and W. Longmore
(Australian National Wildlife Collection), M. LeCroy
(American Museum of Natural History) and S. Olson and J.
Dean (National Museum of Natural History, Smithsonian Institution)
for access to comparative material; and the Australian
Museum for providing a venue in which to carry out this study.
Systematic Paleontology
Order GALLIFORMES
Family MEGAPODIIDAE
Because of the gracility of the trochleae of the tarsometatarsus
described herein compared with those of some other megapodes,
the Pinpa fossil bears a superficial resemblance to the
tarsometatarsus of a medium-sized pigeon, such as the Wonga
Pigeon, Leucosarcia melanoleuca Latham. Rich et al. (1991)
originally placed it in the Columbidae, which is understandable
because there are superficial similarities between the tarsometatarsus
in these two families, as shown by De Vis's
(1888) original description of the fossil megapode Progura
gallinacea as a relative of the crowned pigeons {Gourd). Van
Tets (1974) discussed characters that differentiate the two
groups.
The tarsometatarsus in the Megapodiidae may be identified
by the following combination of characters: three cristae hypotarsi
(medialis large) and four sulci hypotarsi (medialis broad),
only one of which is enclosed; distal extension of crista media-