Whence Homo floresiensis ? - The Fossil Chronicles - page 172

ened strips (keeling) that run along the midline at the top. The nasal
bones and bony bulges behind the ear (mastoid processes) are also
shaped like those of Homo erectus. Most measurements of the teeth also
align the Dmanisi specimens with Homo erectus. Interestingly, other
characteristics seem to be unique in the Dmanisi hominins, such as two
separate keels along the top of the cranium.
This hodgepodge of traits led to a disagreement about the species
identification for the Dmanisi fossils, with some scientists placing them
in early Homo erectus, Homo ergaster, or even a new species, Homo georgicus . 56
What was needed to help clarify the nature of the Dmanisi hominins,
of course, was a partial skeleton to compare with the little, apelike aus-
tralopithecines and the remains of taller, leggier African Homo erectus.
Happily, such a skeleton was described in September 2007 by David
Lordkipanidze, of the Georgian National Museum, and his colleagues . 57
The skeleton was from an adolescent who was several years older than
the Homo erectus boy (WT 15K). As a bonus, the discovery also included
various postcranial bones (that is, from below the head) of three other
individuals.
The cranial capacity of the adolescent had been estimated earlier
(from skull D2700) at approximately 600 cm 3 , and the newly described
postcrania that go with this skull suggest that he or she (the sex is
unclear) was around five feet tall, compared with WT 15K's approxi-
mate five feet three inches. 58 Although the youth's cranial capacity is the
smallest among the Dmanisi specimens, the individual was probably
very nearly the size of an adult when he or she died. (This is consistent
with another fragmentary skeleton from Dmanisi that was estimated
to be just slightly taller than this youth.) Even so, this small capacity
indicates that brain size at Dmanisi had increased by at least a third
beyond the australopithecine average of 450 cm 3 . However, the post-
cranial remains had also increased in size, which suggests that relative
brain size was smaller than that of the bigger-brained and somewhat
taller boy from Kenya (Nariokotome) . 59 Although not much can be said
about the cognitive abilities of the Dmanisi hominins, it is worth not-