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Three partial femora from Quarries I and M of the early Oligocene Jebel Qatrani Formation in the Fayum of Egypt are attributed to Aegyptopithecus zeuxis on the basis of their appropriate size and anthropoid morphology. Compared with extant catarrhines, Aegyptopithecus is unusual in having a distinct gluteal tuberosity (third trochanter) and a relatively deep distal femoral articulation. In the estimated neck angle, Aegyptopithecus resembles arboreal quadrupeds rather than either leaping or suspensory primates. It seems likely that the femur of this species was relatively robust and short for its body mass. In aspects of its femoral anatomy, Aegyptopithecus is quite different from the parapithecid Apidium and more similar to Catopithecus from late Eocene deposits of the Fayum, and also to small hominoids from the Miocene of East Africa. KEY WORDS Egypt; locomotion; Catopithecus; proconsulid

Yarala burchfieldi n. gen. and sp. is described from Oligo-Miocene deposits of Riversleigh Station, northwestern Queens-land. Although the smallest and most plesiomorphic bandicoot known, it shares unique synapomorphies with other peramelemorphs, such as the posteriorly orientated preparacrista on [M.sup.2], posterolingual location of the hypoconulids, and the buccal position of the centrocrista. However, Y. burchfieldi lacks synapomorphies that would unambiguously allow it to be placed in any of the modern families as currently understood. In its plesiomorphic features, Y. burchfieldi provides a structural link between peramelemorphs and dasyuromorphs and appears to be a descendant of an annectant group that separated long prior to the origin of 'typical' bandicoots. This species is present in many sites within the Riversleigh area. It possibly filled an insectivorous-carnivorous niche presently occupied by small dasyurids that are relatively more abundant today than they were when the Riversleigh deposits accumulated.

A new species of the extinct aplodontid genus Prosciurus is described from the Orellan (Oligocene) of North Dakota and Nebraska. The upper dentition of this species shares several features with the primitive Asian meniscomyine aplodontid Promeniscomys and is, therefore, believed to represent an ancestral type for later meniscomyine aplodontids.

Ischyromys, the most abundant early Oligocene rodent from the Great Plains, has been considered by some workers to represent a single gradually evolving lineage comprising three or more chronospecies. Statistical investigation of large samples suggest instead that two closely related species coexisted, and the shift in mean size that was thought to represent anagenesis actually represents replacement. In Nebraska and eastern Wyoming both I. parvidens (small) and I. typus (large) were rare but of equal abundance in the Chadronian, I. parvidens was more prevalent in the early Orellan, and I. typus was more prevalent in the middle and late Orellan. In northeastern Colorado, northern South Dakota, and North Dakota I. typus is the only species of Ischyromys found in Orellan deposits, thus showing that the two species had differing geographic ranges. The mean size of I. typus does increase up section at all localities, but this change is minor and not deserving of chronospecies recognition. Much of this change occurred in the latest Orellan and earliest Whitneyan as I. typus approached extinction, and it was accomplished mostly by loss of small individuals rather than a shift of the entire distribution. Rate of evolutionary change in Ischyromys is found to be inversely correlated with population size, and no new species arose during the Orellan when Ischyromys was most abundant.

Very well preserved specimens of a macruran decapod from the Lower (Lacustrine) Member of the Nirihuau Formation, northwestern Patagonia, Argentina, permitted description of Lammuastacus longirostris, a new genus and species of Parastacidae. The sedimentological and paleontological evidences provided by the faunal assemblage indicate a freshwater environment. This is the first certain record of a fossil Parastacidae from Tertiary deposits, most probably Oligocene. The fossil material shows similarities with Geocharax, the extant Australian genus considered to retain many primitive characters, and other related genera from New Zealand and Chile.

An assemblage of well-preserved octocoral holdfasts and sclerites has been collected from the Red Bl the Chickasawhay River, Wayne County, Mississippi. Seven families were identified, utilizing a colle sclerites. Families represented are Telestidae, Nephtheidae, Anthothelidae, Paramuriceidae, Plexauri These families, with exception of the Gorgoniidae, are here reported for the first time as fossils f The collection represents one of the most diverse fossil octocoral assemblages known from a single l, An assemblage of about 1,000 sclerites and 62 holdfasts from the Red Bluff Formation at Chickasawhay River, Wayne County, MS, yielded specimens from seven families of octocorals. Difficulties with classification of disarticulated scerites prevented identification to the species level. The families Telestidae, Anthothelidae, Paramuriceidae, Nephtheidae, Plexauridae, Virgulariidae and Gorgonidae are represented. With the exception of Gorgonidae, this is the first report of the occurrence of members of these families in the Gulf Coast region.

A large, diverse, and well-preserved fauna of nonmarine mollusks has been recovered from the late Oligocene to early Miocene (Arikareean) fluviatile and lacustrine sediments that accumulated in four intermontane structural basins of western Montana. The Pupillidae are represented by 10 species, with nine new species and one new subgenus among three extant genera. The Gastrocopta are very diverse, with one new subgenus Ameralbinula represented by three new species, G. obesa, G. russelli, and G. oviforma, while three new species, G. tavennerensis, G. leonardi, and G. Conica are referred to the extant subgenus Vertigopsis Sterki, 1893. Gastrocopta miniscula cannot be referred to a subgenus with certainty. The remaining new species, Vertigo whitei and Pupoides montana, are referred confidently to extant subgenera. Vertigo arenula (White, 1876) is the only previously described species and its description is emended based on new material. The mammalian biostratigraphy of the Cabbage Patch beds is presented.

A nearly complete skull of Parapithecus grangeri from the early Oligocene of Egypt is described. The specimen is relatively undistorted and is undoubtedly the most complete higher primate skull yet found in the African Oligocene, which also makes it the most complete Oligocene primate cranium worldwide. Belonging in superfamily Parapithecoidea, a group regarded by some as the sister group to all other Anthropoidea, this skull reveals important information about the radiation of stern anthropoideans. This cranium is about 15% larger than size estimates based on a fragmentary cranium of its contemporary and close relative Apidium phiomense. It is about the same size as that of the gray gentle lemur, Hapalemurgriseus, or of platyrrhines such as the owl monkey, Aotus trivirgatus, or the titi monkey, Callicebus torquatus. Comparatively small orbits and size differences in jaws and teeth show it was both diurnal and dimorphic. This is the only specimen of the species that shows (from sockets) that there were four small upper incisors. Several mandibular specimens of the species establish that there were no permanent lower incisors and that the symphysis was fused. Like other early anthropoideans this species possessed a lower encephalization quotient and less-developed orbital frontality than later anthropoideans. There is full postorbital closure and fusion of the metopic suture, and the ectotympanic forms a rim to the auditory aperture. A probable frontal/ alisphenoid contact is a potentially derived resemblance to Catarrhini. A proposed separate genus for the species P. grangeri is not sustained.

A freshwater interbed of the Yemen Volcanic Group in central western Yemen yielded impressions of numerous, articulated, mostly complete frog skeletons. Recent dating of the volcanics and the stratigraphic position of the fossil bearing bed in the sequence support a Late Oligocene age for the frogs. These frogs are described as a new species of Xenopus, a genus that is today mostly confined to subsaharan Africa, and they provide evidence of the former, wider distribution of this genus on the Afro-Arabian Plate. The new species, X. arabiensis, differs from other Xenopus in its long maxilla and maxillary tooth row. It resembles X. muelleri in its dentate, azygous vomer and prominent, cone-shaped, distally-pointed prehallux, but differs from X. muelleri in having an atlantal intercotylar notch and longer distal prehallux bone. Climatic changes during the Neogene probably led to the extinction of Xenopus on the Arabian Peninsula; however, the timing of this event is not certain.

In this paper, we provide evidence that contrary to the current view, primates on the European continent did survive the dramatic extinction/origination event across the Eocene/Oligocene boundary 34 million years ago that severely affected the Eurasian mammal communities (the European 'Grande Coupure' and the Asian 'Mongolian Remodeling'). The survival of a mouse-sized omomyid for at least 2 million years, recorded in two localities of the Lower Stampian (Lower Oligocene) in a well dated stratigraphic series of fluviatile sediments in the north oriental sector of the Ebro Basin (Northeastern Spain), reflects the size-related survival pattern described recently for other coeval mammalian taxa.

A fossil fauna found in the Chilean Andes, which is about 34 million years old, and includes fossils of a rodent, helps trace the emergence of rodents in South America and reinforces the assumption that they originated in Africa. Rodents are members of caviomorphs, the breed that includes guinea pigs. Rodents probably used the currents and oceanic rises of the South Atlantic in the Early Oligocene era to move to South America from Africa by island-hopping.

An almost complete specimen of the irregular echinoid species Macropneustes mortoni was discovered in the Florala Limestone of the Lower Oligocene (Vicksburgian) of southern Alabama. Before this discovery, M. mortoni was reported only from the Upper Eocene of Alabama, Georgia and Florida. The find is significant because it proves that, contrary to what was previously thought, M. mortoni was one of the few Eocene echinoids to survive the extinctions of the Eocene-Oligocene in the Gulf Coastal Plain. It also corroborates the age assignment of the Florala Limestone to the Vicksburgian.