Postcranial Osteology Research Articles

The postcranial skeleton of Proterorhinus marmoratus with remarks on the relationships of the genus Proterorhinus (Teleostei: Gobiidae)

The postcranial osteology of the Ponto-Caspian tubenose goby Proterorhinus marmoratus is described and its relevance to the systematic position of Proterorhinus is discussed. Proterorhinus marmoratus differs significantly from the gobioids of the Ponto-Caspian and Atlantic-Mediterranean in the anterior displacement of the origin of the first dorsal fin. The first dorsal-fin pterygiophore of the tubenose goby inserts in the second interneural space between the neural spines of the second and third vertebrae. The first pterygiophore of the other gobioids inserts in the third interneural space between the neural spines of the third and fourth vertebrae. The increased number of precaudal and caudal vertebrae and the dorsal pterygiophore formula starting with 2-12 in Proterorhinus marmoratus are derived character states. This 2-12 starting sequence and a single interneural space anterior to the first dorsal-fin pterygiophore are unique for gobioids and autapomorphies of Proterorhinus. It is proposed that Proterorhinus be placed in the subfamily Gobiinae.

Comparative osteology of early Tertiary tapiromorphs (Mammalia, Perissodactyla)

Characters of cranial and postcranial osteology provide important data for examining the interordinal relationships of mammals. Understanding variation in the cranial and postcranial skeleton is necessary for adequately representing ancestral character states for each mammalian order. This paper provides a comprehensive description and discussion of cranial and postcranial osteology in one of the major perissodactyl lineages, the Tapiromorpha, the lineage including the extant rhinoceroses and tapirs and their fossil relatives. Tapiromorph skeletal morphology is described, and tapiromorphs are compared to each other, to other perissodactyls, and to a number of other eutherians. Characters of potential phylogenetic significance are emphasized. A phylogenetic analysis of tapiromorphs using cranial and postcranial osteological characters provides a number of interesting results. The data do not support placing Homogalax and Chalicotherioidea within Tapiromorpha. The data support several novel hypotheses regarding the phylogeny of rhinocerotoids, including a close relationship between rhinocerotids and amynodontids, relative to hyracodontids. Finally, examples of the relevance of tapiromorph osteology to understanding perissodactyl origins are discussed, particularly new interpretations of certain primitive character states for perissodactyls.

The Emergence of whales: evolutionary patterns in the origin of Cetacea

Synopsis of the Earliest Cetaceans: Pakicetidae, Ambulocetidae, Remingtonocetidae, and Protocetidae E.M. Williams. Middle to Late Eocene Basilosaurines and Dorudontines M.D. Uhen. Molecular Evidence for the Phylogenetic Affinities of Cetacea J. Gatesy. Are Cetaceans Highly Derived Artiodactyls? M.C. Miliknovitch, et al. Phylogenetic and Morphometric Reassessment of the Dental Evidence for a Mesonychian and Cetacean Clade M.A. O'Leary. Relationships of Cetacea to Terrestrial Ungulates and the Evolution of Cranial Vasculature in Cete J.H. Geisler, Z. Luo. Middle Eocene Cetaceans from the Harudi and Subtahu Formatons of India S. Bajpai, J.G.M. Thewissen. Postcranial Osteology of the North American Middle Eocene Protocetid georgiacetus R.C. Hulbert, Jr. Homology and Transformation of Cetacean Ectotympanic Structures Z. Luo. Biomechanical Perspective on the Origin of Cetacean Flukes F.E. Fish. Implications of Vertebral Morphology for Locomoter Evolution in Early Cetacea E.A. Buchholtz. Structural Adaptations of Early Archaeocete Long Bones S.I. Madar. Evolution of Thermoregulatory Function in Cetacean Reproductive Systems D.A. Pabst, et al. 3 Additional Chapters. Index.

Neogene History of Anniella Gray, 1852 (Squamata, Anniellidae) with Comments on Postcranial Osteology

California, from approximately the San Francisco Bay south into Baja California, Mexico, and a few coastal Pacific islands. The oldest known fossil specimens of Anniella were recovered from late Miocene sediments in the San Francisco Bay area. We report 18 new Pliocene and Pleistocene fossil localities for Anniella, all from within the modern geographic distribution of the genus. Morphological variation in the vertebral column permits diagnosis of 10 distinct regions or individual vertebrae, and many of these are now known from the fossil record. Previous studies have shown that soil moisture, ground temperature, soil texture and vegetation cover play an important role in limiting the distribution of the genus today. If these same parameters were operating in the past, the presence of Anniella in fossil deposits may provide some indication of local paleoenvironmental conditions. Despite analyses of both morphological and molecular characters, the precise phylogenetic position of Anniella remains unresolved.

Osteology of the Myobatrachine Frog Arenophryne rotunda Tyler (Anura: Leptodactylidae) and Comparisons with other Myobatrachine Genera

Cranial and post-cranial osteology of the headfirst-burrowing Australian myobatrachine frog, Arenophryne rotunda, are described and compared with the genera Myobatrachus, Pseudophryne, Uperoleia and Ranidella. Some anatomical features, such as the position of the nasal bones, the form of the occipital condyles and the orientation of the coracoids, are considered to be burrowing adaptations, whilst other features reflect phylogenetic affinities. The highly paedomorphic nature of the skull is unique among the genera examined.

Postcranial Osteology of the Waterfowl

Postcranial osteology of nearly all the genera of waterfowl of the world is described. On the basis of this study certain changes in the classification within the order are proposed. In comparison with the most recent classification of the waterfowl that of Delacour, the following changes are proposed: Anseranas is placed in a monotypic family; Stictonetta is removed from the Anatini and placed tentatively in the Dendrocygnini of the Anserinae; Cereopsis is moved from the Tadornini to a monotypic tribe of the Anserinae; Plectropterus is moved from the Cairinini to the Tadornini; Tachyeres is moved from the Tadornini to the Anatini; the tribe Cairinini is merged with the Anatini; Merganetta is moved from the Anatini to a monotypic tribe; Rhodonessa is moved from the Anatini to the Aythyini; the tribe Somateriini is merged with the Mergini. The following genera are resurrected: Olor, Nesochen, Cattonetta, Pteronetta, Metopiana, Mergellus, Lophodytes, and Nomonyx, and, tentatively, Asarcornis and Salvadorina.