The Phylogeny of the Myrmecophagidae (Mammalia, Xenarthra, Vermilingua) and the Relationship of Eurotamandua to the Vermilingua

A cladistic investigation of the phylogenetic relationships among the three extant anteater genera and the three undoubted extinct myrmecophagid genera is performed based upon osteological characteristics of the skull and postcranial skeleton. One hundred seven discrete morphological characters are analyzed using the computer program PAUP. Characters are polarized via comparison to the successive xenarthran outgroups Tardigrada (represented by the living sloth Bradypus) and Cingulata (represented by the recent armadillos Dasypus and Euphractus). The analysis results in a single most-parsimonious tree (TL = 190, CI = 0.699, RI = 0.713). The tree corroborates the monophyly of the subfamilies Cyclopinae and Myrmecophaginae, the former including the extant Cyclopes and the Pliocene genus Palaeomyrmidon. Within the Myrmecophaginae the Miocene genus Protamandua is the sister taxon to a clade including the remaining three genera. The recent Tamandua is in turn the sister taxon to the extant Myrmecophaga plus the Pliocene genus Neotamandua. Contrary to the suggestions of recent authors, weak support is provided for the taxonomic distinctiveness of the latter genus from the recent Myrmecophaga. The monophyly of the Myrmecophagidae is supported by 15 unequivocal synapomorphies. The monophyly of the Cyclopinae and Myrmecophaginae is supported by 3 and 13 unambiguous synapomorphies, respectively. The enigmatic Eocene genus Eurotamandua, from the Messel fauna of Germany, is coded for the 107 morphological characters above and included in two subsequent PAUP analyses. The palaeanodont Metacheiromys is also added to these two analyses as a nonxenarthran outgroup to test for the possibility that Eurotamandua lies outside the Xenarthra. In the first analysis, Eurotamandua is constrained a priori to membership in the Vermilingua. The single most-parsimonious tree (TL = 224, CI = 0.618) that results places Eurotamandua as the sister group to the remaining anteater genera, contra Storch and Habersetzer's (1991) assignment of Eurotamandua to the vermilinguan subfamily Myrmecophaginae. Eurotamandua shares six unequivocal synapomorphies with other anteaters, including the absence of teeth and the presence of a lateral tuberosity on the fifth metatarsal. The remaining vermilinguans are united by 11 unequivocal synapomorphies, plus an additional 10 ambiguous synapomorphies. In the second analysis, the position of Eurotamandua is unconstrained. The resulting single most-parsimonious tree (TL = 219, CI = 0.632) places Eurotamandua outside Vermilingua as the sister group to the Pilosa (Vermilingua plus Bradypus). The monophyly of this node is supported by four unambiguous synapomorphies in the unconstrained analysis. Further manipulation of this second analysis shows that placement of Eurotamandua as the sister group to the Xenarthra or to the Palaeanodonta adds three steps to the shortest tree but is more parsimonious than its placement as a sister group to the Vermilingua is the previous analysis. The addition of pangolins to the analysis does little to alter the major phylogenetic conclusions of the study. The allocation of Eurotamandua to the Xenarthra, but as a sister group to the Pilosa, is a novel arrangement which leaves open the biogeographic question of how a xenarthran reached Western Europe during the Eocene.     

Geometric morphometrics of the skull of various murid rodents (Mammalia, Rodentia): relation of the skull shape to the trophic specialization

Presented is a brief overview of basic principles and notions of geometric morphometrics, a new approach to quantitative analysis of shape variations. This approach is applied to analysis of variation of the skull shape in the sample of 18 muroid genera belonging to the families Cricetidae, Arvicolidae and Gerbillidae. The skull shape is described by landmarks, and skulls are compared by resistant fit and superimposition methods. Under consideration is relation of skull shape to the trophic specialization, to family belonging, and to body size. Axial skull reveals more conspicuous relation to each of the factor analyzed as compared to mandible. Zygomatic region and tooth raw are most differentiable, while change of auditory bulla is of secondary effect. Transition from omnivorous through granivorous to grass-eating specialization involves the same trend in each of the family studied in the case of axial skull but not of mandible. Most dependent of trophic specialization appeared to be shape of axial skull rather then of mandible. Arvicolines are most specific in respect to the skull shape. Shape to size relation, although rather slight, also involves the same zygomatic-dental region. The results obtained indicate probably that geometric morphometrics does reveal variations in the skull shape that are free of the size effect.     

Les Lagomerycidae (Artiodactyla, Mammalia) de FranceThe French Lagomerycidae (Cervoidea, Artiodactyla, Mammalia)

The Lagomerycidae, a small family of the Cervoidea, is known in France by the genera Lagomeryx, Ligeromeryx and Stephanocemas. Lagomeryx contains three species, the other two genera one species only. This family is known from MN3 to MN5.     

The first French tragulid skull (Mammalia,Ruminantia, Tragulidae) and associated tragulid remains from the Middle Miocene of Contres (Loir-et-Cher,France)

The Faluns Auger quarry (Contres, France) is famous for its Langhian mammal fauna (MN5) and tragulid remains have been identified as Dorcatherium sp. New excavations provided a fragmented skull of a tragulid, dental remains, and a metapodium which we describe here. Based on morphological and morphometrical characters, these specimens are attributed to Dorcatherium crassum. CT-scans provide insight in the petrosal bone and bony labyrinth. We prove intra-population variability of the p4 and intra-specific variability of the bony labyrinth. Nevertheless, we can demonstrate that the bony labyrinth is useful for systematics. Thus, we confirm the presence of D. crassum in the Pontlevoy–Thenay and Savigné-sur-Lathan Faluns Basins as reported already prior to our study. Yet, we cannot confirm evidence for Dorcatherium naui. D. naui specimens reported from these basins may belong to another species. D. naui should be absent from the Faluns before MN7, such as in the rest of Europe.     

Evolutionary and biogeographical implications of variation in skull morphology of raccoon dogs (Nyctereutes procyonoides,Mammalia: Carnivora)

Morphological characteristics reflect geographical variation resulting from adaptation to varying environmental conditions. Carnivore species distributed over a wide geographical range generally have highly polymorphic morphological variation. The raccoon dog (Nyctereutes procyonoides) has a longitudinal distribution restricted to East Asia and the northern Indochina Peninsula. Its unique geographical range makes it an appropriate model to examine how morphological differences are influenced by geography. To demonstrate morphological evolution of Russian, Chinese, Korean and Japanese raccoon dogs predicted by geographical differences, we tested the island rule and Bergmann's rule. We compared craniodental variation among populations and examined morphological implications for intraspecific taxonomic status. Insular raccoon dogs possessed substantially smaller body size than those from the mainland. Moreover, different island effects among Japanese islands were demonstrated by markedly larger occipital condyle breath in the Hokkaido population. Larger skull size in Russian and Hokkaido raccoon dogs could be explained by Bergmann's rule. Based on previous chromosomal and molecular studies and results of our morphological analyses, we suggest Japanese raccoon dogs are a distinct species from the mainland N. procyonoides.     

Autonomic innervation of salivary glands in the armadillo,anteater, and sloth (Edentata)

The intraglandular distribution of adrenergic and cholinergic nerve fibers was studied histochemically in the parotid, mandibular, and sublingual glands of six species of edentates belonging to the three families that comprise the order; namely, the Dasypodidae (armadillos), the Myrmecophagidae (anteaters), and the Bradipodidae (sloths). The following histochemical techniques were used: (a) acetylcholinesterase reaction for the demonstration of cholinergic fibers; (b) formaldehyde- and glyoxylic acid-induced fluorescence for the demonstration of adrenergic fibers. In addition, norepinephrine (NE) was assayed fluorimetrically in the mandibular and parotid glands of the armadillo. A network of acetylcholinesterase-positive nerve fibers surrounds the intra- and interlobular ducts and endpieces of all glands; it is of low density in the mandibular and sublingual gland of the sloth, of high density in the sublingual gland of the anteater and of moderate density in the remaining glands. A vascular cholinergic innervation occurs in all salivary glands. Although present around the vessels, adrenergic new fibers were virtually absent from the parenchyma of all glands, even after in vitro incubation of glandular tissue with NE, or after administration of NE to armadillos previously treated with a monoamine oxidase (MAO) inhibitor. Consistent with this fact, the amount of NE present in the parotid and mandibular gland of the armadillo was extremely low. These findings may indicate that the salivary secretion in the edentates is regulated by the parasympathetic rather than by the sympathetic nervous system.     

Myology of the Feeding Apparatus of Myrmecophagid Anteaters (Xenarthra: Myrmecophagidae)

The musculoskeletal feeding apparatus of anteaters in the family Myrmecophagidae (Eutheria: Xenarthra) is described, compared among the three extant genera (Tamandua, Myrmecophaga, Cyclopes), and interpreted in a phylogenetic framework. Character polarities are assessed with reference to other xenarthrans, eutherians, and didelphid marsupials. Xenarthrans are widely regarded as basal eutherians, and this is reflected in the apparent retention of plesiomorphic character states in jaw and pharyngeal musculature. Jaw closing muscles are architecturally simple, the stylohyoideus is absent, the stylopharyngeus is robust and architecturally complex, and the superior pharyngeal constrictor is weak. At the same time, the highly specialized trophic ecology of myrmecophagids is reflected in derived features of the jaw, tongue, and palatal musculature. The sternomandibularis is present, the tongue is largely composed of a sternog-lossus with no attachments to the hyoid apparatus, other glossus muscles are modified and do not enter the tongue, and the mylohyoideus and stylopharyngeus contribute to the soft palate, while other palatal muscles vary among the myrmecophagid genera. Feeding apparatus mycology provides further support for myrmecophagid monophyly. Documentation of the morphological transformations that lead to the myrmecophagid condition is hampered by incomplete data on feeding apparatus structure in nonmyrmecophagid xenarthrans (sloths and armadillos) but a tentative character mapping onto an independently derived phylogeny is offered.     

The phylogeny of the Rhinocerotoidea (Mammalia, Perissodactyla)

A new phylogeny of the Superfamily Rhinocerotoidea is proposed, based upon an analysis of shared derived characters of the skull, teeth and skeleton. Hyrachyus is considered the primitive sister-taxon of the three rhinocerotoid families (Amynodontidae, Hyracodontidae, Rhinocerotidae), and the amynodonts appear to be the sister-group of hyracodonts and rhinocerotids. The relationships of primitive hyracodonts and rhinocerotids are clarified. Menoceras and Pleuroceras (new Subfamily Menoceratinae) are removed from the Diceratheriinae, since they appear to be more closely related to higher rhinoceroses than they are to Diceratherium. Of the three major monophyletic groups of higher rhinocerotids (aceratherines, teleoceratines and rhinocerotines), the last two groups are more closely related to each other than either is to aceratherines. Toxotherium and Schizotheroides are tentatively removed from the Rhinocerotoidea and placed in the Lophiodontidae.     

The Diversity and Distribution of the Fruit Bat Fauna (Mammalia, Chiroptera, Megachiroptera) of Danjugan Island, Cauayan, Negros Occidental, Philippines (with Notes on the Microchiroptera)

Bats are the most diverse mammalian order in the Philippines and whilst many endemic and threatened species have been documented, they are also probably the least well-known order. Negros Island (central Visayas, Philippines) represents one of the ten highest-ranking sites globally for megachiropteran diversity, and is listed as a priority area for the establishment of protected areas for megachiropteran conservation. It is also listed as a priority site for survey work. The current study undertook mist-netting, roost and observation surveys of the bat fauna of Danjugan Island, off the west coast of Negros Occidental, to inventory the bat species present and to provide baseline ecological information to identify key areas of conservation concern. Eight species – five megachiropterans and three microchiropterans – were recorded over the course of the study, representing over 10% of the total Philippine bat fauna. Four of the species are new records for the island, and three are IUCN Red Listed. The results show that the island provides important cave- and tree-roosting areas for the local populations of several endemic and globally endangered species and sub-species. Already designated with reserve status, and with an environmental education programme established within the local communities, the island may be considered of national and global importance for bat conservation. Recommendations are given for future management.     

Investigating South American biogeographic history using patterns of skull shape variation on Cerdocyon thous (Mammalia: Canidae)

Patterns of geographic variation of the canid Cerdocyon thous have historically been obscured by its remarkable intraspecific morphological variability. The observed distribution is highly associated with phytophysiognomy, a feature considered highly dynamic along geological time. In the present study, we tested whether vegetation distribution during the Holocene Glacial Maximum of South America (HGM) explains the patterns of morphological variation within Cerdocyon thous . The species was divided in groups according to paleohabitats that could support their presence during the HGM, and then tested for differences in skull morphometrics. The results obtained demonstrate that the climatic changes during the HGM influenced the population structure of this species, resulting in the establishment of geographical groups with different degrees of morphological cohesion. Higher morphological cohesion found in the Northern group might be explained by the marked discontinuity between its geographical range and the rest of the species'distribution. The Eastern and Southern morphological divergence is less striking and, although this could be related to past vegetation distribution, the disappearance of those barriers leads to a population structure that could be slowly breaking down.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 77–84.     

A juvenile skull of Acerorhinus yuanmouensis (Mammalia: Rhinocerotidae) from the Late Miocene hominoid fauna of the Yuanmou Basin (Yunnan,China)

A unique juvenile skull bearing both milk premolars and unerupted but fully developed permanent premolars and molars (observed using X-ray microcomputed tomography), and some isolated upper cheek teeth, all from the Late Miocene hominoid fauna of the Yuanmou Basin (Yunnan, China), closely resemble craniodental material of Acerorhinus yuanmouensis Zong, 1998 from the same locality, and are referred to this species. A phylogenetic analysis based on 214 craniodental morphological characters scored for 31 terminal taxa reveals that A. yuanmouensis should be assigned to the genus Acerorhinus indeed. The newly discovered specimens improve our understanding of this species, especially with respect to the morphology of the milk premolars and premolars. Two intraspecific variations in the upper premolars are noted: a lingual bridge may be present or absent, and the lingual cingulum continuous or reduced. The analysis also indicates that: the phylogenetic status of Acerorhinus lufengensis Deng and Qi, 2009 should be reconsidered; “Aceratherium” huadeensis Qiu, 1979 does neither belong to Aceratherium nor Acerorhinus, and its phylogenetic status remains debatable.     

A revision of the genus Dinofelis (Mammalia, Felidae)

This paper consists of a taxonomic and systematic revision of the extinct felid genus Dinofelis (Felidae, Ma-chairodontinae) and an analysis of its ecomorphology and evolution. Dinofelis has a broad distribution, with material from all northern continents and Africa, the latter of which was the apparent centre of evolution of the genus. We describe new material of Dinofelis from a number of sites in eastern Africa and reconsider all previously described material. We name two new species and identify several other distinct species-level taxa but refrain from naming these due to a paucity of well-preserved material. At the same time, we synonymize the two named Asian species, D. cristata and D. abeli , of which the former has priority. There are few characters useful in systematic analysis, but we can suggest at least one migration from eastern to southern Africa. Ecomorphological analysis of both craniodental and postcranial characters suggests that Dinofelis in many respects converged on modern pantherine cats in morphology and behaviour, a trend culminating in the South African D. barlowi and the Asian D. cristata , which are the most pantherine-like of all machairodont felids. This trend is reversed in the evolution of the youngest species, D. piveteaui , which is also the most machairodont in its ecomorphology. The timing of the extinction of Dinofelis is difficult to determine. Outside Africa material is scarce at all times, while in Africa the apparent extinction of Dinofelis at about 1.4 Mya coincides with the end of the good, semi-continuous fossil record present in eastern Africa from about 4 Mya onwards. Dating of Kanam East (with D. piveteaui) to the Jaramillo Subchron (1.070-0.990 Mya) suggests possible survival considerably later. Thus, the extinction datum for Dinofelis cannot at present be firmly established.     

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.     

On the phylogenetic position of monotremes (Mammalia,Monotremata)

Henosferida from the Middle-Upper Jurassic of Western Gondwana is the most probable sister group for monotremes. They share the derived pretribosphenic structure of lower molars combined with the presumably absent protocone on the upper molars and the plesiomorphic retention of postdentary bones and pseudangular process of the lower jaw. In addition, the two groups share the dental formula with three molars and the position of the Meckel’s groove, which passes ventral to the mandibular foramen. In the course of subsequent evolution, monotremes acquired the mammalian middle ear with three auditory ossicles independently of therian mammals and multituberculates. Jurassic Laurasian Shuotheriidae are probably a sister group of the Gondwanian clade Henosferida + Monotremata. The Jurassic shuotheriid Pseudotribos shows a great plesiomorphic similarity to monotremes in the structure of the pectoral girdle, with a large interclavicle immovably connected to the clavicle. In the lineages leading to therian mammals and multituberculates, the pectoral girdle changed probably independently and in parallel in connection with the establishment of the parasagittal posture of the forelimbs (reduction of the interclavicle, mobile articulation of the interclavicle with clavicle, reduction of the procoracoid, and development of a supraspinous fossa of the scapula) and formation of the mammalian middle ear with three auditory ossicles.     

Response to environmental factors and competition: skull, mandible and tooth shapes in Polish water shrews (Neomys, Soricidae, Mammalia)

Environmental factors and competition in closely related sympatric species may result in character displacement or phenotypic convergence. We studied the effects of sympatry on size and shape of the skulls, mandibles and molars in two species of water shrew, Neomys anomalus and Neomys fodiens . We studied populations from six localities in Poland, three where the species are sympatric (Pomorze, Białowieża, and Bieszczady Mts) and three where only N. fodiens is found. We studied shape and size using geometrical landmarks. The three morphological structures that we studied are expected to respond differently to environment and competition, because they are controlled by different numbers of gene loci, have different developmental patterns and different functional roles. We found strong evidence that shape in all three structures was influenced by local environment and that both species responded to geoclimatic factors in the same way. Indirect evidence suggests that the parallel response of the two species is likely to be ecophenotypic in the case of skulls and mandibles but selective in molars. We found no evidence for character displacement in either size or shape, although significant differences were found between the two species as a whole, and within species between localities. Not only was there any evidence for displacement but also the species were actually more similar when they occurred in sympatry, probably because of the similar ecophenotypic responses to their shared environment.