Omomyiform primates are among the most basal fossil haplorhines, with the oldest classified in the genus Teilhardina and known contemporaneously from Asia, Europe, and North America during the PaleoceneeEocene Thermal Maximum (PETM) ~56 mya. Characterization of morphology in this genus has been limited by small sample sizes and fragmentary fossils. A new dental sample (n ¼ 163) of the North American species Teilhardina brandti from PETM strata of the Bighorn Basin, Wyoming, documents previously unknown morphology and variation, prompting the need for a systematic revision of the genus. The P4 of T. brandti expresses a range of variation that encompasses that of the recently named, slightly younger North American species ‘Teilhardina gingerichi,’ which is here synonymized with T. brandti. A new partial dentary preserving the alveoli for P1-2 demonstrates that T. brandti variably expresses an unreduced, centrally-located P1, and in this regard is similar to that of T. asiatica from China. This observation, coupled with further documentation of variability in P1 alveolar size, position, and presence in the European type species T. belgica, indicates that the original diagnosis of T. asiatica is insufficient at distinguishing this species from either T. belgica or T. brandti. Likewise, the basal omomyiform ‘Archicebus achilles’ requires revision to be distinguished from Teilhardina. Results from a phylogenetic analysis of 1890 characters scored for omomyiforms, adapiforms, and other euarchontan mammals produces a novel clade including T. magnoliana, T. brandti, T. asiatica, and T. belgica to the exclusion of two species previously referred to Teilhardina, which are here classified in a new genus (Bownomomys americanus and Bownomomys crassidens). While hypotheses of relationships and inferred biogeographic patterns among species of Teilhardina could change with the discovery of more complete fossils, the results of these analyses indicate a similar probability that the genus originated in either Asia or North America.
Located in
Library
/
RBINS Staff Publications 2019
The objective of the present revision is to complement the lithostratigraphy of the Ieper Group published in 2001 (Laga et al., 2001). This last publication reflected the activities in the Tertiary Subcommission at that time. The review published in 2001 framed in an initiative of the National Stratigraphic Commission and was limited to the lithostratigraphy at formation level. The Laga et al (2001) reference document has been the basis for the NCS website until now. The Ieper Group is characterised by clay−dominated sediments overlying, in most situations, the Landen Group strata and, if not outcropping, underlying the sand−dominated Zenne Group sediments. According to Laga et al. (2001) in their reference document for Paleogene and Neogene lithostratigraphy, the Ieper Group consists of the Kortrijk, Tielt and Gentbrugge Formations and ,members in these Formations are only listed. These subdivisions are also used on the 1:50 000 geological maps of Flanders, edited in the last decades of the 20th century. Especially the additional description of the members, and where possible, horizons, identified in the Formations, made the present review necessary and also modifications at the formation level itself arisen since 2001 needed to be integrated in a new synthesis. The present update is based on the earlier description of members in Maréchal & Laga (1988), Geets et al. (2000) and Steurbaut (1998) as far as appropriate. All modifications, discussions and additions are supported by the relevant literature references.
Located in
Library
/
RBINS Staff Publications 2016
Although questions of modern human origins and dispersal are subject to intense research within and outside Africa, the processes of modern human diversification during the Late Pleistocene are most often discussed within the context of recent human genetic data. This situation is due largely to the dearth of human fossil remains dating to the final Pleistocene in Africa and their almost total absence from West and Central Africa, thus limiting our perception of modern human diversification within Africa before the Holocene. Here, we present a morphometric comparative analysis of the earliest Late Pleistocene modern human remains from the Central African site of Ishango in the Democratic Republic of Congo. The early Late Stone Age layer (eLSA) of this site, dated to the Last Glacial Maximum (25–20 Ky), contains more than one hundred fragmentary human remains. The exceptional associated archaeological context suggests these remains derived from a community of hunter-fisher-gatherers exhibiting complex social and cognitive behaviors including substantial reliance on aquatic resources, development of fishing technology, possible mathematical notations and repetitive use of space, likely on a seasonal basis. Comparisons with large samples of Late Pleistocene and early Holocene modern human fossils from Africa and Eurasia show that the Ishango human remains exhibit distinctive characteristics and a higher phenotypic diversity in contrast to recent African populations. In many aspects, as is true for the inner ear conformation, these eLSA human remains have more affinities with Middle to early Late Pleistocene fossils worldwide than with extant local African populations. In addition, cross-sectional geometric properties of the long bones are consistent with archaeological evidence suggesting reduced terrestrial mobility resulting from greater investment in and use of aquatic resources. Our results on the Ishango human remains provide insights into past African modern human diversity and adaptation that are consistent with genetic theories about the deep sub-structure of Late Pleistocene African populations and their complex evolutionary history of isolation and diversification.
Located in
Library
/
RBINS Staff Publications 2016
