SAMBUNGMACAN
(Sambungmacan; also Poloyo)
Lo CATION
The original find of a calvaria (SM 1) was made in
1973 in alluvial deposits on the S bank of the Solo
river, 12 km E of Sragen, Central Java, Indonesia. Del-
son et al. (2001) have designated this findspot as Sam-
bungmacan Locality 1. In 1977, a surface find of a
tibial fragment (SM 2) was made at a nearby site, also
designated Sambungmacan. The third specimen, an-
other calvaria (SM 3), is believed (although not cer-
tainly known) to have been found in a sandbar in the
Solo river some distance to the south of Locality 1,
near Ngadirejo. This new locality has been dubbed
Sambungmacan Locality 2 (Delson et al., 2001). The
only firm provenance for the SM 3 specimen is, how-
ever, a natural history store in New York City. For rea-
sons of his own, Jacob (see Marquez et al., 2001) has
chosen to designate all of these localities (although,
perhaps remarkably, not the natural history store) as
Sambungmacan, despite the poor documentation and
the probable geographic and (maybe stratigraphic) dis-
tances separating the sites. The initial designation for
SM 3 was Poloyo 1 (see Marquez et al., 2001), which
remains a convenient informal designation to use, in
view of all of the uncertainties involved in the recovery
of this specimen.
DISCOVERY
Collectors working for T. Jacob, 1973 (SM 1); H.
Baba and colleagues, 1977 (SM 2); anonymous collec-
tor, possibly as early as 1977, although announced
only in 2001 (SM 3).MATERIAL
Almost complete adult calvaria (SM l), tibial frag-
ment (SM 2); fairly complete calvaria (SM 3).DATING AND STRATIGRAPHIC CONTEXT
The fossiliferous deposits at Sambungmacan Local-
ity 1 (SM 1) lie at a depth of about 8 m in an artifi-
cial excavation dug for flood control on the Solo
river (Jacob et al., 1978). The SM 1 hominid was re-
portedly found in situ in a sandy layer assigned to
the Middle Pleistocene Kabuh Fm by Jacob (1976).
However, Sartono (1979) reported that there were
no Kabuh sediments in the area and instead identi-
fied these deposits as Late Pleistocene sediments
lying unconformably on the Pliocene Kalibeng Fm.
The associated fauna is said to have both Djetis and
Trinil components. However, both of these faunas
are very poorly characterized, hence this observation
does not materially assist in dating. Polarity of the
fossil beds is normal (Jacob et al., 1978); this sug-
gests an age of less than 700 Ka unless the Jaramillo
event (1 Ma to 980 Ka) is recorded, in which case
Jacob‘s initial faunal estimate of 900 Ka would have
been only a modest underestimate. Either way, an
age of under 1 Ma is indicated. The SM 2 tibial
fragment has been compared on the basis of fluorine
content to specimens correlative to the Kabuh
sediments of Sangiran (Matsu’ura et al., 1990), an
attribution corroborated by later multielement
analyses (Matsu’ura et al., 2000); but such prove-
nance still remains to be confirmed. The SM 3472