4,4'-Dimethyldinaphtho[a,d]cycloheptane, a naturally occurring polyaromatic derivative related to triterpenoids of the serratane series.

[reaction: see text] The polyaromatic hydrocarbon 4,4'-dimethyldinaphtho[a,d]cycloheptane (1a) has been identified by NMR studies after isolation from an Oligocene sediment. The original symmetrical structure of 1a, which bears a central seven-membered ring, is closely related to higher plant triterpenoid precursor(s) of the serratane series and is believed to have been formed in the subsurface by a microbially mediated aromatization process.

Discovery of a second human molar and cranium fragment in the late Middle to Late Pleistocene cave of Ma U'Oi (Northern Vietnam).

In November 2002, during the second season of work by a Vietnamese-French-Japanese team, we discovered a human molar and a fragment of an occipital bone in the late Middle to Late Pleistocene cave of Ma U'Oi (Bacon et al., Geobios. 37 (2004) 305). The layer from which this material comes is the same as that in which a human lower molar was found in 2001. Both molars can be attributed to archaic Homo, and both exhibit archaic and modern traits.