Inventory of remains of Hominidae from Pliocene-Pleistocene formations of the lower Omo basin, Ethiopia (1967-1972)

Since its initiation in 1966 the Omo Research Expedition has recovered a series of hominid fossils, in association with many vertebrate taxa, from formations of Pliocene/Pleistocene age from the lower Omo basin, southern Ethiopia. These fossiliferous formations span a time range from over 4.2 m.y. to about 1.4 m. y. on the basis of K/A age determination. Hominid remains have been found so far to occur at two localities in the upper part of the Usno Formation (～ 2.9 m.y.) and in the Shungura Formation at 79 localities from successive Members B through levels postdating J, a time span between 3 m.y. and 1.4 m.y. The remains—inventoried here according to skeletal part, locality and stratigraphic level, age and situation—include numerous isolated and associated teeth, mandibles, partial maxillae, portions of crania, and elements of the postcranial skeleton.     

The oldest marine vertebrate fossil from the volcanic island of Iceland: a partial right whale skull from the high latitude Pliocene Tjörnes Formation

Extant baleen whales (Cetacea, Mysticeti) are a disparate and species‐rich group, but little is known about their fossil record in the northernmost Atlantic Ocean, a region that supports considerable extant cetacean diversity. Iceland's geographical setting, dividing North Atlantic and Arctic waters, renders it ideally situated to shed light on cetacean evolution in this region. However, as a volcanic island, Iceland exhibits very little marine sedimentary exposure, and fossil whales from Iceland older than the late Pleistocene are virtually unknown. Here, we present the first fossil whale found in situ from the Pliocene Tjörnes Formation (c. 4.5 Ma), Iceland's only substantial marine sedimentary outcrop. The specimen is diagnosed as a partial skull from a large right whale (Mysticeti, Balaenidae). This discovery highlights the Tjörnes Formation as a potentially productive fossil vertebrate locality. Additionally, this find indicates that right whales (Eubalaena) and bowhead whales (Balaena) were sympatric, with broadly overlapping latitudinal ranges in the Pliocene, in contrast to the modern latitudinal separation of their living counterparts.     

The Balearic Islands: a reservoir of cpDNA genetic variation for evergreen oaks

Aim To analyse the role of the Balearic Islands as a refuge area for evergreen Quercus (cork oak: Quercus suber L., holm oak: Q. ilex L., kermes oak: Q. coccifera L.), by using molecular, historical and palaeobotanical data. Location The Western Mediterranean Basin (Balearic Islands, eastern Iberia, Provence, Sardinia, Corsica, Sicily, Malta, Italy, Northern Africa). Methods We sampled 108 populations and used the PCR‐RFLP technique with five universal cpDNA primers to define haplotypes in the sampled populations. Diversity, differentiation parameters and spatial analysis of the populations, using a spatial version of amova , were linked to the geological history of the Western Mediterranean Basin in order to explain the present spatial pattern of the evergreen Quercus populations in the Balearics. Results Evergreen Quercus cpDNA shows a complex structure, with remnants of ancient diversity in the Balearics. Balearic populations of holm oak are related to Iberian populations, while for cork and kermes oaks, we found both Tyrrhenian and Iberian haplotypes. Main conclusions The complex spatial patterns of cpDNA in Balearic evergreen Quercus appears explicable in terms of a combination of physical (vicariance and long distance dispersal) and biological (introgressive hybridization) factors. The Balearics constitute a glacial refuge area and a reservoir of genetic variation with traces of ancient diversity from Messinian–Pliocene stages.     

A new global biome reconstruction and data-model comparison for the Middle Pliocene

Aim To produce a robust, comprehensive global biome reconstruction for the Middle Pliocene (c. 3.6–2.6 Ma), which is based on an internally consistent palaeobotanical data set and a state‐of‐the‐art coupled climate–vegetation model. The reconstruction gives a more rigorous picture of climate and environmental change during the Middle Pliocene and provides a new boundary condition for future general circulation model (GCM) studies. Location Global. Methods Compilation of Middle Pliocene vegetation data from 202 marine and terrestrial sites into the comprehensive GIS data base TEVIS (Tertiary Environmental Information System). Translation into an internally consistent classification scheme using 28 biomes. Comparison and synthesis of vegetation reconstruction from palaeodata with the outputs of the mechanistically based BIOME4 model forced by climatology derived from the HadAM3 GCM. Results The model results compare favourably with available palaeodata and highlight the importance of employing vegetation–climate feedbacks and the anomaly method in biome models. Both the vegetation reconstruction from palaeobotanical data and the BIOME4 prediction indicate a general warmer and moister climate for the Middle Pliocene. Evergreen taiga as well as temperate forest and grassland shifted northward, resulting in much reduced tundra vegetation. Warm‐temperate forests (with subtropical taxa) spread in mid and eastern Europe and tropical savannas and woodland expanded in Africa and Australia at the expense of deserts. Discrepancies which occurred between data reconstruction and model simulation can be related to: (1) poor spatial model resolution and data coverage; (2) uncertainties in delimiting biomes using climate parameters; or (3) uncertainties in model physics and/or geological boundary conditions. Main conclusions The new global biome reconstruction combines vegetation reconstruction from palaeobotanical proxies with model simulations. It is an important contribution to the further understanding of climate and vegetation changes during the Middle Pliocene warm interval and will enhance our knowledge about how vegetation may change in the future.     

Prolagus italicus n. sp. (Ochotonidae, Lagomorpha), a new Pliocene species of peninsular Italy

Prolagus italicus n. sp., a new endemic Pliocene species of peninsular Italy, is described here, adding new details to the knowledge of this widespread and long-lasting ochotonid genus. Several dental morphodimensional characters suggest a close relationship between P. italicus and P. sorbinii (evaporitic and postevaporitic Messinian, central Italy). On the other hand, P. italicus shares with other Plio-Pleistocene Prolagus species of continental Europe a large size and some peculiar characters of dental occlusal surface. Actually, an evolutionary trend can be detected in Plio-Pleistocene species of the genus Prolagus. The value of P. italicus in biochronology is quite consistent, as this species seems to mark MN17 in central Italy. Moreover, some morphodimensional differences between P. italicus populations have been identified: this can help to infer relative chronological positions to the fossil sites in which P. italicus is present. Some morphological characters present in one of the two available P. italicus populations are apparently related to ecological more than to evolutionary factors: this may be a starting point for in-depth palaeoecological studies related to the genus Prolagus. The presence of P. italicus in the Italian peninsula may have prevented the entrance of other species of western European affinity.     

An Upper Pliocene <Emphasis Type="Italic">Equisetum</Emphasis> (Equisetales) from the Atotonilco El Grande Formation in Central Mexico

The present work documents the occurrence of Equisetum in the Upper Pliocene deposits of Central Mexico, describing and comparing fossil taxa with modern specimens. All taxonomic characters suggest a close affinity to the modern species Equisetum myriochaetum Schldl. et Cham. This work, which records the first Upper Pliocene occurrence of Equisetum in Central Mexico, confirms the wide distribution of the genus in high latitudes and more humid climates.     

A new species of Haborophocoena, an Early Pliocene phocoenid cetacean from Hokkaido, Japan

A new species of phocoenid cetacean Haborophocoena , collected from the Early Pliocene Embetsu Formation, in the close vicinity to the site where the holotype of the type species of the genus Haborophocoena was retrieved, improves our knowledge of the anatomy of this cetacean. The new species, represented by a skull, lacking distal half of the rostrum, ear bones, and teeth, is significantly smaller than, but morphologically similar to, the type species Haborophocoena toyoshimai Ichishima and Kimura 2005 . This new record of Haborophocoena confirms the veracity of the genus Haborophocoena as a biological entity, contributes to understanding the interspecific variation, and suggests that the genus diversified in the northwestern Pacific of early Pliocene time. The adult-like degree of ossification in this small skull precludes it from being a juvenile of Haborophocoena toyoshimai . Autapomorphies of Haborophocoena minutus include narrow premaxilla on the dorsal surface of the rostrum, the anterior position of the premaxillary foramen, and a distinct ridge dividing a fossa on the lateral face of the base of the zygomatic process into the dorsal and the ventral halves, the zygomatic process rectangular in lateral profile, and its small size, which is the most compelling feature, making it a distinct species.     

Phylogeny and systematics of the Orycteropodidae (Mammalia,Tubulidentata)

The systematics of the order Tubulidentata is poorly known. Its phylogeny has never been thoroughly analysed and only a single review has ever been performed, which was over 30 years ago. This situation has hampered palaeoecological and palaeobiogeographical studies of these Neogene mammals. The present revision of the Orycteropodidae deals with the phylogeny and systematics of all African and Eurasian species over the last 20 Myr. The first comprehensive cladistic analysis of the family is presented here. The results of this analysis, based on 39 coded morphological characters, supplemented by non‐coded features taken from all over the skeleton, was used to reconstruct the phylogeny of the order Tubulidentata. Two distinct lineages within the genus Orycteropus are recognized and characterized. The new genus Amphiorycteropus is subsequently created, in order to harmonize taxonomy and phylogeny. The fossil genera Leptorycteropus and Myorycteropus are validated, bringing the number of genera in the order Tubulidentata to four. Moreover, within the family Orycteropodidae, the number of confirmed species is now 14. The outcome of this study allows us to propose a consistent palaeobiogeographical scenario for aardvarks. Finally, this revision represents the most comprehensive work on the evolutionary history of the order Tubulidentata to date, and provides a new framework for future studies. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 649–702.     

Tragelaphus nakuae: evolutionary change,biochronology, and turnover in the African Plio‐Pleistocene

Fossil Bovidae constitute one of the most significant proxy records for evolutionary and palaeoecological change in Africa. Tragelaphus nakuae is a regularly encountered antelope in the East African Plio‐Pleistocene, and is a common component of hominin faunas. As previously understood, this species ranged for almost 2 million years, encompassed a large range of morphological variation, exhibited relative stasis in the face of environmental perturbations, and left no known living descendants. I here review and revise the fossil record of this tragelaphin bovid, finding that specimens older than ～2.8 Mya and previously attributed to T. nakuae or a close form are in fact referable to a distinct, but ancestral, species. This new interpretation adds these fossil tragelaphins to the body of evidence supporting major faunal turnover occurring around 2.8 Mya in concert with global climatic change. I also document morphological changes that occur through the duration of T. nakuae, particularly after 2.3 Mya. These taxonomic revisions allow for refined biochronological estimates for several East African Plio‐Pleistocene sites and specimen assemblages of uncertain age. A phylogenetic analysis suggests that the T. nakuae lineage is related to the extant bongo (Tragelaphus eurycerus), relating this living but enigmatic forest antelope to the fossil record. One resulting palaeoecological hypothesis is that the bongo's modern fragmented range represents the relicts of a much more widely distributed late Pliocene African forest belt. This study highlights the importance of specimen‐based approaches for elucidating the pattern and timing of major evolutionary events. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 699–711.     

南海莺琼盆地渐新世—上新世孢粉组合序列及其古环境意义

本文对莺琼盆地新生代的孢粉资料进行了综合梳理,划分出6个特征明显的孢粉组合。根据孢粉组合的特征及具有时代意义的化石分子对地层的时代进行划分,探讨了各个时代的植被类型、气候条件及沉积环境。孢粉组合显示,莺琼盆地陵水组/三亚组出现的孢粉组合差异大,气候条件发生了较大突变,由偏凉干向偏暖湿变化,是古近纪/新近纪的界线。