External brain anatomy in relation to the phylogeny of Caninae (Carnivora: Canidae)

Caninae is one of the most studied mammalian groups, nevertheless there are relatively few comparative studies on their neuroanatomy. This work contributes to a better knowledge of this subfamily, since it describes the external cerebrum anatomy of 29 out of the 35 living Caninae species, 11 of which are described for the first time. Information about their frontal region appears to be a welcome supplement to the study of the phylogeny. Two distinctive features are recognized, that can be traced back in the fossil record: the sulcal pattern medial to the coronal sulci, and the shape and relative size of the proreal gyrus. Four types are described for the first feature: (1) orthogonal: Canis, Lycaon, Cuon, Atelocynus, Speothos , (2) pentagonal: Vulpes, Alopex, Otocyon, † Eucyon , (3) parenthesis-like: † Dusicyon, Pseudalopex, Chrysocyon , (4) heart-shaped: Urocyon, Cerdocyon, Pseudalopex culpaeus, Nyctereutes . Three types are described for the second feature: (1) elongated and bilaterally compressed: Canis, Cuon, Lycaon, Atelocynus, Speothos, Cerdocyon, † Dusicyon, Chrysocyon, Pseudalopex , † Nyctereutes sinensis , † N. tingi , (2) small: Vulpes, Otocyon, Urocyon, Alopex , (3) wide and low: Nyctereutes procyonoides. On the basis of these features some phylogenetic interpretations are presented: the fossil Asian Nyctereutes is close to Cerdocyon, Speothos is close to Atelocynus , Chrysocyon is not related to Canis , Urocyon differs from Vulpes and Pseudalopex culpaeus differs from the rest of the Pseudalopex species.  © 2003 The Linnean Society of London. Zoological Journal of the Linnean Society , 2003, 138 , 505–522.     

Coralline red algal assemblage from the Middle Pliocene shallow-water temperate carbonates of the Monte Cetona (Northern Apennines,Italy)

During the Pliocene and Pleistocene, the Monte Cetona (Northern Apennines, central Italy) was part of an elongated island. The Middle Pliocene deposits around the Monte Cetona are represented by shallow-water marine carbonates rich in coralline red algae and bryozoans. These skeletal carbonates, characterising a coralline algal-dominated factory, were analysed in terms of microfacies, taxonomy, and growth-forms of coralline red algal assemblage. Three microfacies were distinguished on the basis of component distribution and fabric analysis: coralline algal rudstones, coralline algal floatstones, and bioclastic packstones. Skeletal components are commonly abraded, bioeroded, and encrusted. The shallow-water skeletal carbonates are strongly bioturbated and any primary sedimentary structure is obliterated. The distribution of the coralline growth-forms suggests a decreasing hydrodynamic gradient from the coralline algal rudstone, through the coralline algal floatstone to the bioclastic packstone microfacies. The coralline algal flora consists of eight species representing the subfamilies Lithophylloideae, Mastophoroideae and Melobesioideae. The assemblage is dominated by lithophylloids. Other biogenic components are bryozoans, barnacles, echinoderms, and benthic foraminifera. These coralline algal assemblages were deposited just above the fair-weather wave base and indicate a shallow-marine temperate water setting for the eastern Tyrrhenian Sea during the Mid Pliocene.     

Macroecology and evolution of a crab ‘super predator’, Menippe mercenaria (Menippidae), and its gastropod prey

It is widely accepted that the fossil record shows both the evolution of more powerful durophagous marine predators through time and, in response, major shifts in life mode and morphology for many prey taxa. Few fossil studies, however, have successfully identified particular predator species with respect to causing evolutionary change in particular prey species. We present evidence that the evolutionary appearance in the western Atlantic of the stone crab, Menippe mercenaria, an extraordinarily powerful durophagous predator, contributed to the appearance of sinistrality, which is very rare, in two genera of marine gastropods (Conus and Sinistrofulgur) during the Pliocene. Based on this conclusion, we suggest that modern fishing pressure on stone crabs may lead to evolutionary changes in their present day prey.     

From ‘third pole’ to north pole: a Himalayan origin for the arctic fox

The ‘third pole’ of the world is a fitting metaphor for the Himalayan–Tibetan Plateau, in allusion to its vast frozen terrain, rivalling the Arctic and Antarctic, at high altitude but low latitude. Living Tibetan and arctic mammals share adaptations to freezing temperatures such as long and thick winter fur in arctic muskox and Tibetan yak, and for carnivorans, a more predatory niche. Here, we report, to our knowledge, the first evolutionary link between an Early Pliocene (3.60–5.08 Myr ago) fox, Vulpes qiuzhudingi new species, from the Himalaya (Zanda Basin) and Kunlun Mountain (Kunlun Pass Basin) and the modern arctic fox Vulpes lagopus in the polar region. A highly hypercarnivorous dentition of the new fox bears a striking resemblance to that of V. lagopus and substantially predates the previous oldest records of the arctic fox by 3–4 Myr. The low latitude, high-altitude Tibetan Plateau is separated from the nearest modern arctic fox geographical range by at least 2000 km. The apparent connection between an ancestral high-elevation species and its modern polar descendant is consistent with our ‘Out-of-Tibet’ hypothesis postulating that high-altitude Tibet was a training ground for cold-environment adaptations well before the start of the Ice Age.     

Evidence for a Late Pliocene faunal transition based on a new rodent assemblage from Oldowan locality Hadar A.L. 894, Afar Region, Ethiopia

The time interval between 3 Ma and 2 Ma marks several important transitions in human evolution, including the extinction of Australopithecus afarensis, the origin of the genus Homo, and the appearance of concentrated stone tool assemblages forming recognizable archaeological sites. The period also marks important changes in Earth’s climatic history, with the onset of northern hemisphere glaciation starting sometime between 2.8 Ma and 2.5 Ma, and it remains an unresolved question in paleoanthropology whether or not the global climatic events influenced in whole or in part, local terrestrial paleoenvironments in Africa and, through this, the course of human evolution.Changes in the terrestrial mammalian faunas of East Africa during this time interval are an important source of data about terrestrial paleoenvironments, and it has been argued that during this time period the mammalian faunas of Africa experienced a sudden pulse in the extinction and origination of taxa. The data corroborating this Turnover Pulse Hypothesis derive from both large mammal and micromammal data, though the fossil record of the former is much more abundant in this interval. New micromammal fossils recovered from ca. 2.4 Ma deposits at locality A.L. 894, low in the Busidima Formation in the Hadar study area of the Afar region, Ethiopia, reveal a significant faunal turnover when compared with previously published material from older 3.2 Ma micromammal assemblages from the Hadar Formation deposits. The results support the hypothesis of a major faunal transition, but larger sample sizes and more extensive temporal sampling are needed to refine the time and rate of change within this interval at Hadar.     

New cranial material of Shansirhinus (Rhinocerotidae, Perissodactyla) from the Lower Pliocene of the Linxia Basin in Gansu, China

A well-preserved skull and articulated mandible of Shansirhinus, a horned aceratherine rhinocerotid, is described from an Early Pliocene (Gaozhuangian; approximately 5.3-4.34 Ma) locality of the Linxia Basin in Gansu, China. Comparing the new material of Shansirhinus ringstromi Kretzoi, 1942, we confirm the synonymy proposed previously for the species Chilotherium yunnanensis Tang et al., 1974, Chilotherium cornutum Qiu and Yan, 1982, and Ch. tianzhuensis Zheng, 1982. New knowledge concerning its cranial and mandibular morphology allows insight into its phylogenetic position among aceratherine rhinocerotids. A sister group relationship between Shansirhinus and Chilotherium is proposed on the basis of cranial, mandibular and dental evidence. Shared derived characters that support this relationship include: an expanded mandibular symphysis with a concave ventral surface; retracted premaxillae lacking upper incisors; a robust and right-angled facial crest; a flat or slightly concave dorsal skull profile; a weak or absent parastyle fold; and a constricted protocone on the premolars. Shansirhinus was probably a grazer, which is evidenced by the high crown, strong wear, well-developed secondary folds, and enamel plications on its teeth. The age of S. ringstromi is Late Miocene to the Early Pliocene, corresponding to the Turolian to Ruscinian, MN12-MN15 of Europe. S. ringstromi is likely the ancestor of the more advanced S. brancoi (Schlosser, 1903).     

Orycteropus (Tubulidentata, Mammalia) from Langebaanweg and Baard's Quarry, Early Pliocene of South Africa

Fossil teeth and bones of aardvarks are relatively common at Langebaanweg, an Early Pliocene site in western Cape Province, South Africa. The remains are compatible in size and most details of morphology to extant Orycteropus afer, and are the earliest fossils attributed to this species. Other Late Miocene to Early Pliocene localities in Africa have yielded smaller species of aardvarks, suggesting that the extant lineage evolved in southern Africa. Morphologically the genus Orycteropus has been remarkably conservative since at least the Early Miocene but it witnessed an overall increase in size through the Neogene. The species O. afer has been morphometrically stable since the Early Pliocene. These observations indicate that the evolutionary process in aardvarks is extremely bradytelic. To cite this article: M. Pickford, C. R. Palevol 4 (2005).     

Cercopithecidae from the Pliocene Chiwondo beds, Malawi-rift

There are a total of 16 fossil cercopithecid specimens, representing at least 10 individuals, from the Chiwondo Beds of northern Malawi. The majority of this material is derived from the Middle Pliocene Unit 3A, but one specimen is from the Early Pliocene Unit 2. This latter specimen is from a papionin of indeterminate genus similar in size to Parapapio ado and Pliopapio alemui. Among the specimens from Unit 3A, two species can be diagnosed: an indeterminate species of Theropithecus, and a species of Parapapio similar in dental size to P. broomi. Neither of the genera from Unit 3A are exclusive to either East Africa or South Africa. Their relative abundances, however, are more similar to Middle Pliocene South African sites where Parapapio is the most common primate genus, and Theropithecus is comparatively rare. This is in contrast to similarly-aged East African sites where Theropithecus is by far the most abundant genus.     

Pliocene ostracods of Southwestern Europe

This paper analyzes the lithostratigraphic features and ostracod associations of the Pliocene deposits located in the western sector of the Guadalquivir basin (SW Spain). A regressive cycle is defined by the vertical distribution of five main facies (FA-1 to FA-5), which were deposited in upper bathyal to fluvial palaeoenvironments. The broad palaeontological record is utilized to draw a general outline of the food chain in each palaeoenvironment. A comparison with the Pliocene ostracod distribution of southeastern Spain, southwestern France and Portugal permits to define a common ostracod biozonation for southwestern Europe during this period. Four main marine biozones are distinguished: (a): Pontocythere elongata biozone (infralittoral); (b): Costa edwardsii biozone (shallow circalittoral); (c): Bosquetina carinella biozone (deep circalittoral); and (d): Henryhowella asperrima biozone (upper bathyal). Freshwater, brackish and lower bathyal/abyssal species are very scarce in this area during this period.     

New fossil fruits of Carya (Juglandaceae) from the latest Miocene to earliest Pliocene in Tennessee,eastern United States

Fossil fruits including nuts and associated husk valves of a new species of Carya (Juglandaceae) are described from the latest Miocene to earliest Pliocene in northeastern Tennessee, eastern United States. The husk valves are elliptic, 1.2–4.5 mm thick, with a convex exterior face and a concave interior face; the nuts are globose to ovoid in shape, smooth and longitudinally ribbed on exterior surface, with a short protruding apex and a slightly 4-angled base; inner ribs, lacunae and primary septa are well-developed, while secondary septa are absent or weakly developed. The combination of these carpological characteristics clearly shows a close resemblance to the genus Carya in Juglandaceae. Detailed comparisons of carpological morphology and anatomy indicate that the present fossil taxon is different from both living and most other fossil species of the genus, and therefore warrants the designation of a new fossil species, Carya tennesseensis Huang et al., sp. nov. Carya tennesseensis displays a carpological similarity to C. ventricosa from the late Oligocene to early Pliocene in Europe, suggesting a potential species exchange of the genus between Europe and southeastern North America during the late Neogene. The new fossil species represents one of the few fruit fossil species of Carya from its modern distribution range in southeastern North America. It provides crucial information for better understanding the rapid diversification of the genus from the late Miocene to early Pliocene, and the origin and establishment of today's Carya biodiversity in this region.