Postcranial functional adaptations in the South American Miocene borhyaenoids (Mammalia,Metatheria): Cladosictis,Pseudonotictis and Sipalocyon

Three Santacrucian borhyaenoids, Cladosictis patagonica, Pseudonotictis pusillus and Sipalocyon gracilis, are analyzed from a functional-adaptive perspective. Five extant placentals and one marsupial model are also examined in order to interpret the locomotor adaptations of these fossils. Pseudonotictis pusillus is the smallest of the Santacrucian borhyaenoids and is known from fragmentary remains; from its small size, dental specializations and elbow anatomy, this species was certainly not far ecologically from an extant weasel. The postcranium of Sipalocyon gracilis, although poorly known, suggests climbing capabilities, and the pseudo-opposable pollex indicates skilful manipulative behaviour. Cladosictis patagonica was an active predatory form, short-legged and able to climb, although it was a less specialized arboreal form than the contemporaneous Prothylacinus patagonicus; the proportions of its limbs recall that of a living South American marten, the tayra. The pseudo-opposable pollex of Cladosictis, as in Sipalocyon, indicates skilful manipulative behaviour.     

Evolutionary morphological changes in the new genus Duoforisa: implication for classification and habitat of the unilocular Foraminifera

Qianyu Li & Brian Mcgowran, 1994:03:28. Evolutionary morphological changes in the new genus Duoforisa: implication for classification and habit of the unilocular Foraminifera. Alcheringa 18, 121–134. ISSN 0311-5518.

Unlike other unilocular foraminifera, the new genus Duoforisa from the Late Oligocene to Early Miocene possesses a kidney-shaped test with two apertures on its distal ends. It contains two distinct and successional species, both new, and differentiated by their apertural details. In Duoforisa rima the apertures are slit-like, and become radial in the descendant D. diducta. Intermediate forms have transitional apertural configurations between the slit type and radial type, accompanied also by a change of the test outline from subtriangular to compactly U-shaped. The evolution of the lineage occurred during a period of enhanced upwelling in the Early Miocene and it was terminated just before the global warming at the Early-Middle Miocene boundary. This example suggests evolution of the unilocular foraminifera through successional morphological changes in test shape and in the aperture. Unilocular taxa have tended to flourish or speciate in cool or upwelling environments. Their contraction in the latest Early Miocene to early Middle Miocene was probably due to global warming and well oxygenated conditions which were widespread in the neritic domains of southern Australia.     

Morphological changes in the shape of the non‐pathological bony knee joint with age: a morphometric analysis of the distal femur and proximal tibia in three populations of known age at death

This study examines possible morphological variation in the knee joint of Homo sapiens with increasing age in ostensively healthy and non‐pathological distal femora and proximal tibiae. Throughout the lifetime of each individual, the hard tissue of the knee undergoes considerable remodelling as a response to biomechanical stresses, changes in bone microarchitecture and reduction of bone mineral content as a concomitant of ageing. The knee is also subject to greater levels of degenerative joint disease than any other joint. If death occurs whilst such diseases are in the earliest stages, initial bone changes may not be visually obvious in museum specimens. If such specimens are used for comparative analyses, it is hypothesised that changes might render it problematic if all ages are conglomerated into discrete samples. This study therefore investigates the degree to which the distal femur and proximal tibia change shape during ageing and, if changes are present, whether they are expressed similarly in males and females. It also examines whether changes are of greater magnitude than those morphological differences which might exist between populations. In an example population of African‐Americans, results indicate that there is a statistically significant difference in shape between age groups and those differences become progressively greater between the youngest and oldest adults. Results also show that although morphological variation caused by ageing is apparent, those shape differences attributable to sexual dimorphism are more powerful. When two additional populations are analysed jointly with the African‐Americans (Caucasian Americans and the European Spitalfields sample), results indicate that inter‐population shape differences are considerably greater than differences caused by increasing age. Results imply that it is justifiable to combine specimens of all ages into discrete samples for comparative purposes. Copyright © 2007 John Wiley & Sons, Ltd.     

Miocene wood from the LaTrobe Valley coal measures,Victoria, Australia

An initial study of a collection of fossil conifer wood is reported from the late early Miocene Yallourn Clays, an interseam unit intergrading into the base of the early to middle Miocene Yallourn seam of the LaTrobe Valley, Victoria in southeastern Australia. The fossil wood shares characteristics with the modem genera Dacrycarpus and Dacrydium. On the basis of contiguous, uniseriate tracheid pitting and 1–2 podocarpoid cross field pits, it is placed in the form genus Podocarpoxylon, and the new species P. latrobensis. The wood is compared with extant Podocarpaceae and other Australian fossil woods. Its ring anatomy is consistent with low temperature or rainfall seasonality in the early Miocene.     

A second species of the possum Durudawiri (Marsupialia: Miralinidae) from the early Miocene of Riversleigh,northwestern Queensland

Durudawiri anfractus sp. nov. (Marsupialia: Miralinidae) is described from Riversleigh. This, the second described species of the genus, is very similar in morphology to, but much larger than, D. inusitatus. Durudawiri anfractus and D. inusitatus are found at similar sites, all early Miocene. The Miralinidae remains one of the most time-restricted families of marsupial, being found so far in only the late Oligocene and early Miocene.     

The southernmost records of Anhingidae and a new basal species of Anatidae (Aves) from the lower–middle Miocene of Patagonia,Argentina

New bird fossils from the Santa Cruz Formation (lower–middle Miocene), Santa Cruz Province, Patagonia, Argentina, are described. They represent an indeterminate species of the extinct anhingid Macranhinga and a new genus and species of basal Anatidae Ankonetta larriestrai. The record of the giant darter Macranhinga constitutes the southernmost record for the family, and expands the known stratigraphic range of the genus, previously restricted to the upper Miocene. Based on an analysis of the fossil anhingid record from South America, we hypothesize that giant darters disappeared from South America in the early Pliocene due to climatic deterioration, regression of marine and freshwater environments, the arrival of placental carnivorous mammals, and also probably by competition with phalacrocoracid cormorants. The new anatid Ankonetta is based on an incomplete but informative tarsometatarsus, with superficial similarities to extant Dendrocygna. A brief overview of several fossil ducks from the Patagonian Cenozoic concludes that most pre-Pliocene examples belong to non-anatine taxa, indicating that plesiomorphic ducks were the dominant anseriforms in those times, a pattern also evident on other continents.     

Early Miocene bivalves from the Cape Melville Formation,King George Island,West Antarctica

Seven species of marine bivalves, including six new taxa, are described from the Cape early Miocene Melville Formation which crops out on the Melville Peninsula, King George Island, West Antarctica. The bivalve assemblage includes representatives of the families Nuculidae, Ennucula frigida sp. nov., E. musculosa sp. nov.; Malletidae, Neilo (Neilo) rongelii sp. nov.; Sareptidae, Yoldia peninsularis sp. nov.; Limopsidae, Limopsis psimolis sp. nov.; Hiatellidae, Panopea (Panopea) sp. cf. P. regularis; and Pholadomyoida (Periploma acuta sp. nov.). Species studied come from four sedimentary sections measured in the upper part of the unit. Detailed morphologic features of nucloid and arcoid species are exceptionally well preserved and allow for the first time reconstruction of muscle insertions as well as dentition patterns of Cenozoic taxa. Known geological distribution of the species is in agreement with the early Miocene age assigned to the Cape Melville Formation. The bivalve fauna from Cape Melville Formation is the best known from Antarctic Miocene rocks, a time of complex geologic, paleogeographic and paleoclimatic changes in the continent. The new fauna introduces new taxonomic and palaeogeographic data that bear on the question of opening of sea gateways and distribution of Cenozoic biota around Antarctica.     

Fossil marsupial predators of South America (Marsupialia,Borhyaenoidea): bite mechanics and palaeobiological implications

Borhyaenoids were marsupial predators that inhabited South America during the Cenozoic. They were very significant because no other mammals rivaled them as terrestrial hunters of large prey. Here we estimate the bite force of three species of borhyaenoids by two different methods to infer predatory behaviour in extinct taxa. One of the methods uses mainly the skull and only some simple measurements of the mandible; the other uses several measurements within the dentary. The results show that bite forces are very high in comparison to predators of the order Carnivora, a feature manifest by several other living and extinct marsupial predators. Differences in size, bite mechanics and special adaptations among the borhyaenoids suggest a very wide range of predatory behaviours that rival those represented in the extant families of the Order Carnivora.     

Two new camerate crinoid species from the Permian of eastern Australia

The habitat and habit of Australia's first recorded Tertiary marsupial species, Wynyardia bassiana, found some 130 years ago at Wynyard on the northwestern coast of Tasmania, remain enigmatic (Aplin 1987, Aplin &; Rich 1990). Fossil pollen and spores preserved in a rafted clast of estuarine silts from the same sequence of earliest Miocene marine sandstones as the skeletal remains indicate the local vegetation was Nothofagus-gymnosperm evergreen rainforest, probably with a cryptogam-rich rather than woody subcanopy stratum. Comparisons with present-day Nothofagus rainforests suggest that, although the subcanopy would have been sufficiently open to allow the passage of a large ground-dwelling herbivorous marsupial, limited food resources are more consistent with Wynyardia being a generalist arboreal herbivore.     

Phylogenetic implications of macropodid (Marsupialia: Macropodoidea) posteranial remains from Miocene deposits of Riversleigh,northwestern Queensland

A new sthenurine taxon, Rhizosthenurus flanneryi gen. et sp. nov. from middle late Miocene deposits of Riversleigh, northwestern Queensland, is established on the basis of material previously assigned to Bulungamayinae. Postcranial remains belonging to an indeterminate basal macropodid are described. Cladistic analysis of 50 discrete postcranial characters coded for 16 ingroup and two outgroup taxa suggests that R. flanneryi is the most plesiomorphic member of a clade containing the late Miocene macropodid Hadronomas puckridgi and crown-group sthenurines. The indeterminate basal macropodid is placed as the immediate sister taxon to the bulungamayine Ganguroo bilamina and a monophyletic clade containing macropodines and sthenurines. This arrangement supports consideration of bulungamayines as ancestral to other macropodids and suggests that macropodines and sthenurines are monophyletic. However, the possibility of a diphyletic origin for Macropodinae and Sthenurinae from within Bulungamayinae cannot be dismissed.     

Humeral morphology of the early Eocene mekosuchine crocodylian Kambara from the Tingamarra Local Fauna southeastern Queensland,Australia

Stein, M., Salisbury, S.W., Hand, S.J., Archer, M. & Godthelp, H., December 2012. Humeral morphology of the early Eocene mekosuchine crocodylian Kambara from the Tingamarra Local Fauna southeastern Queensland, Australia. Alcheringa 36, 473–486. ISSN 0311-5518.

Mekosuchines (Crocodylia; Crocodyloidea) were a clade of crocodylians endemic to Australia and the South Pacific that underwent radiation during the Cenozoic. Numerous questions about mekosuchine palaeoecology remain unanswered. Tantalizing among these is the possibility that some mekosuchines were primarily terrestrial. To date, studies of mekosuchines have focused mainly on the cranium. However, the morphological signal for terrestriality is more likely to be found in the postcranial skeleton. Here, we present a comparative morphological study of fossil humeri referable to Kambara from the early Eocene Tingamara Local Fauna, Murgon, southeastern Queensland. The humeri of Kambara do not show the torsion between the proximal and distal extremity seen in extant crocodylians, illustrated here with Crocodylus porosus and Crocodylus johnstoni. They also differ in the structure of the medial and lateral condyles of the distal extremity. When the effects of these features on musculature and articulation are considered, it appears that the forelimb of Kambara could have facilitated a greater force at the glenohumeral joint and possibly swung the lower forelimb faster with a greater arc of motion than Australia's extant crocodylians. This is conducive to an improved capacity for both terrestrial locomotion and paraxial swimming. Although the former case suggests that Kambara may not have been as closely tied to water as extant crocodylians, it is unusual given the typically broad rostra of the cranium. Among crocodylians this is a common characteristic of semi-aquatic ambush predators. This study shows the utility of the postcranial skeleton in interpreting crocodylian palaeoecology.

Michael Stein [michael.stein@student.unsw.edu.au] (corresponding author), Suzanne J. Hand [s.hand@unsw.edu.au], Michael Archer [m.archer@unsw.edu.au] and Henk Godthelp [h.godthelp@unsw.edu.au], School of Earth and Environmental Science, University of New South Wales, Sydney, NSW, 2052, Australia; and Steven W. Salisbury [s.salisbury@uq.edu.au], School of Biological Sciences, University of Queensland, Brisbane, Qld, 4072, Australia. Received 13.1.2012, revised 24.2.2012, accepted 28.2.2012.     

Miralinidae (Marsupialia: Phalangeroidea) from northern Australia,including the youngest occurrence of the family

Five isolated molars from two localities in the Northern Territory, the middle Miocene Bullock Creek and late Oligocene Kangaroo Well sites, are assigned to the new miralinid genus Barguru, which includes the three new species: Barguru kayir, Barguru maru and Barguru kula. The Miralinidae was previously thought to be restricted to the late Oligocene and early Miocene, but the occurrence at Bullock Creek extends the time range of this family into the middle Miocene. Analysis of metaloph development in the Miralinidae suggests that loph formation in this family followed a different trajectory to that of phalangerids.     

Significance of diadematid echinoid ossicles in micropalaeontological samples,Miocene–Pliocene of Indonesia

Fragments of diadematoid echinoids from the early and middle Miocene, and late Miocene–Pliocene, respectively, of Java, Kalimantan and Sulawesi, Indonesia, are identified as diadematid spp. indet. (radioles from all sites) and Centrostephanus sp. (an interambulacral plate; early Miocene, Java). The radioles are probably a mixture of Diadema ± Centrostephanus ± Echinothrix. This is the first report of identifiable fossil diadematoid remains from Indonesia and demonstrates that these echinoids, so common in modern reef environments, were present in the Neogene of the region. Even though classified in open nomenclature, Centrostephanus sp. nevertheless provides further evidence for the Cenozoic record of a genus in which the only nominal species are of Late Cretaceous and Holocene age.     

First record of Procariama simplex Rovereto, 1914 (Phorusrhacidae,Psilopterinae) in the Cerro Azul Formation (upper Miocene) of La Pampa Province; remarks on its anatomy,palaeogeography and chronological range

Vezzosi, R.I., June 2012. First record of Procariama simplex Rovereto, 1914 (Phorusrhacidae, Psilopterinae) in the Cerro Azul Formation (upper Miocene) of La Pampa Province; remarks on its anatomy, palaeogeography and chronological range. Alcheringa, 157–169. ISSN 0311-5518.

New records of Procariama simplex in central and northwestern Argentina are reported. The fossil material includes mandibular bones, cervical vertebrae and several elements of the fore and hindlimbs. After an exhaustive comparison of anatomical characters and morphometric analysis, the fossil specimens are assigned to the psilopterine Procariama simplex. The specimen from La Pampa Province represents the first record of a psilopterine in this central region of Argentina and derives from upper Miocene sediments of the Cerro Azul Formation. Lithological features and biostratigraphical data allow the host bed to be assigned to the Huayquerian faunal stage (late Miocene). The La Pampa record broadens the geographical distribution of Procariama simplex, which was previously restricted to northwestern Argentina.

Raúl Ignacio Vezzosi [vezzosiraul@gmail.com], Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción CICYTTP-CONICET, Materi y España s/n (3105), Diamante, Entre Ríos, Argentina. Received 1.4.2011, revised 28.5.2011, accepted 14.6.2011.     

Fruits and leaves with cuticle of Laurelia otagoensis sp. nov. (Atherospermataceae) from the early Miocene of Otago (New Zealand)

Conran, J.G., Bannister, J.M. & Lee, D.E., 2013. Fruits and leaves with cuticle of Laurelia otagoensis sp. nov. (Atherospermataceae) from the early Miocene of Otago (New Zealand). Alcheringa 37, 496–509. ISSN 0311-5518.

Laurelia otagoensis sp. nov. Conran, Bannister & D.E. Lee (Laurales: Atherospermataceae) is described from the earliest Miocene Foulden Maar diatomite deposit, Otago, New Zealand. The new species is represented by mummified fossil leaves with well-preserved cuticle and associated clusters of achenes bearing persistent, long plumose styles. This basal angiosperm family is of significance because of its classic southern disjunctions and ecological importance in extant Gondwana-type rainforests, but has a very sparse fossil record. The present study describes one of very few convincing leaf fossils for Atherospermataceae and the only definitive fossil fruits. The presence of fossil Laurelia in Oligo–Miocene New Zealand combined with fossil leaf impressions from the late Eocene, Miocene dispersed cuticle and pollen from the Oligocene to Holocene shows that the family has had a long history in Cenozoic New Zealand. These new fossils also support palaeoclimatic data suggesting warmer conditions in the earliest Miocene of New Zealand.

John G. Conran [john.conran@adelaide.edu.au], Australian Centre for Evolutionary Biology & Biodiversity and Sprigg Geobiology Centre, School of Earth and Environmental Sciences, Benham Bldg DX 650 312, The University of Adelaide, SA 5005 Australia; Jennifer M. Bannister [jennifer.bannister@xtra.co.nz], Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand; Daphne E. Lee [daphne.lee@otago.ac.nz], Department of Geology, University of Otago, PO Box 56, Dunedin, New Zealand. Received 17.12.2012; revised 9.4.2013; accepted 15.4.2013.     

Deciduous Nothofagus leaves from the Miocene of Cornish Head,New Zealand

Pole, M.S., 1994:03:28. Deciduous Nothofagus leaves from the Miocene of Cornish Head, New Zealand. Alcheringa 18, 79–83. ISSN 0311-5518.

Nothofagus leaves with plicate vernation, indicating a deciduous habit, are recorded from the Late Miocene of New Zealand. This is the first unequivocal record in New Zealand of deciduous Nothofagus, deciduous species now being restricted to Tasmania and South America.     

An investigation of the frequency of squatting facets in Later Stone Age foragers from South Africa

Distinctive morphological changes attributed to a habitual squatting posture were observed on the distal femur, distal tibia and on the talar neck of Later Stone Age (LSA) foragers. The frequency of squatting in LSA foragers (n = 56) was determined by the presence of anatomical features of joint hyperflexion. Three South African comparative skeletal groups from different time periods were also analysed: skeletal remains of early farming populations (n = 17), 18th century ‘Free Blacks’ and/or slaves from Cobern Street, Cape Town (n = 21), and a modern cadaver sample (n = 29). The results show that 28 out of 56 LSA foragers (50%) were habitual squatters; 13 out of 17 farmers (76.5%) and one of 21 individuals from the Cobern Street collection (4.8%) demonstrated squatting facets. No anatomical squatters were found in the modern cadaver sample. There was no significant sex difference between squatters and non‐squatters. Hence at least half of the LSA foragers and farmers were habitual squatters, according to the signs of joint hyperflexion. Squatting is a comfortable position for those used to it because the body weight is supported with minimal muscular activity. Two probable reasons are suggested for the difference in postures adopted by the different groups: (1) availability or lack of availability of furniture and (2) cultural and individual differences in resting posture. Copyright © 2005 John Wiley & Sons, Ltd.