MOJOKERTO
(Modjokerto)
Lo CATION
Area of fossiliferous deposits in east-central Java,
Indonesia, to the W of Surabaya. There is some
debate as to the exact hominid locality; Jacob (in
OaMey et al., 1975) locates it 3 km N of Perning
village and 15 km E of Mojokerto.
DISCOVERY
Tjokrohandoj 0,193 6.
MATERIAL
Partial calvaria of an infant.
DATING AND STRATIGRAPHIC CONTEXT
The Mojokerto hominid is classically described as
coming from beds of the Pucangan Fm containing a
Djetis fauna (Duyfjes, 1936). Various sites satisfying
this lithostratigraphic and biostratigraphic descrip-
tion have produced fission-track ages of between
1.16 and 1.51 Ma (Suzuki et al., 1985). These con-
flict strongly with a K/Ar date of 0.5 Ma (rt0.3 Ma)
for allegedly similar sediments published by Bartstra
(1978), but are a little more in line with a K/Ar date
of 1.9 Ma given by Jacob and Curtis (1971) for a
whole-rock sample from a site at Mojokerto believed
to lie stratigraphically fairly close below the
hominid. This latter age for the Mojokerto infant is,
on the face of it, strongly supported by a single-
crystal 40Ar/39Ar date of 1.81 Ma given by Swisher
et al. (1994) for a pumice sample that these authors
believed to be from the Mojokerto hominid site.
This age agrees with the paleomagnetic analysis by
Swisher et al. indicating normal polarity compatible
with the Olduvai Subchron. Yet, strong doubts per-
sist (A. Thorne and others, personal communication)
as to the correct identification of this locality, which,
in turn, casts a shadow on the undoubtedly techni-
cally excellent date. The exact age of the Mojokerto
hominid thus remains in question, especially since
there is no directly associated fauna and the speci-
men may have been redeposited. Still, an earlier
rather than a later Pleistocene date looks increasingly
plausible.ARCHAEOLOGICAL CONTEXT
None.PREVIOUS DESCRIPTIONS AND ANALYSES
The Mojokerto hominid was originally decribed by
von Koenigswald (1936) as Homo modjokertensis, but
in later publications this author referred to it as
“ Pitheca n thropus rob ustus ’’ and ‘Pitheca n throp us mod-
jokertensis” (von Koenigswald, 1940, 1950). Together,
von Koenigswald and Weidenreich (1939) concluded
that the Mojokerto infant was simply a baby
“Pithecanthropus)) (=Homo erectus), while Grimm
(1940) found it to resemble both Peking Man and
the Neanderthals. Campbell (1964) viewed it as only
subspecifically distinct from Zhoukoudian Homo
erectus. Given the tender age and incompleteness of
the specimen, plus its uncertain date, commentators
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