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1.
Abstract:  A new Pleistocene megatheriine, Megatherium celendinense sp. nov., is reported from a cave in the north of the Peruvian Andes. It is the largest Andean Megatheriinae and is characterized by a short, massive, Y-shaped premaxilla unfused to the maxilla, a dorsoventrally compressed occiput perpendicular to the dorsal plane of the cranial roof, prominent and posteriorly extended occipital condyles, an extremely reduced deltopectoral crest and a poorly marked musculospiral groove on the humerus, a rectilinear anterior margin of the distal epiphysis of the tibia, a concave lateral margin of the fibula, discoid and ectal facets of the astragalus clearly separated in dorsolateral view, and a pedestaled articular facet for the meso-entocuneiform on the ectocuneiform. The monophyly of the subfamily is confirmed. ( Pyramiodontherium , Megatheriops , Megatherium and Eremotherium ) constitute a monophyletic clade and ( Pyramiodontherium , Megatheriops ) and ( Eremotherium , Megatherium ) are sister groups. The genus Megatherium includes two clades: ( M. altiplanicum , M. americanum ), subgenus Megatherium , and an Andean lineage ( M. sundti , M. urbinai , M. celendinense sp. nov., M. tarijense , M. medinae ), subgenus Pseudomegatherium . Anatomical characters suggest a more quadrupedal stance for Andean Megatheriinae (Ecuador, Peru, Bolivia and Chile) than those from lower altitude regions.  相似文献   

2.
Abstract:  A new fauna of Lower Cretaceous (Albian) ichthyosaurs, which includes at least one new genus and species, was recovered from deposits of the Loon River Formation at Hay River, Northwest Territories, Canada. All Cretaceous ichthyosaurs have been referred to a single genus, Platypterygius . The Loon River Formation material, however, does not satisfy the diagnosis for Platypterygius , and it is distinctive enough to warrant the erection of a new genus and species of ichthyosaur. Maiaspondylus lindoei gen. et sp. nov. is distinguished from other ichthyosaurs by an extensive overlapping contact of the jugal and the maxilla; marginal teeth with smooth crowns, fluted cementum, lingual curvature and implantation in a dental groove; and humerus with isomorphic proximal and distal ends, featuring three distal articular facets in which the medial articular facet is smaller than the lateral facets. The holotype and referred material is described here, and the relationship of Maiaspondylus to other ophthalmosaurs is discussed.  相似文献   

3.
The giant megatheriine ground sloth Eremotherium eomigrans is described based on remains from the late Blancan to early Irvingtonian (late Pliocene to early Pleistocene) of Florida. It resembles the other giant megatheriines E. laurillardi and Megatherium americanum in size, but is clearly distinguished by a pentadactyl manus. It is assigned to the genus Eremotherium based on two ynapomorphies shared with E. laurillardi: a coarse and rugose ectotympanic that ventrally is prominently expanded mediolaterally, and contiguous articular facets of the axis for the atlas. E. eomigrans is the earliest megatheriine known to have migrated to North America across the Panamanian Land Bridge during the Great American Interchange.  相似文献   

4.
Biomechanical reconstruction is increasingly being applied to the study of the mode of life of fossil animals. Different footprints from the fossil mammal Megatherium sp., the giant ground sloth, seem to indicate that it was able to use either bipedal or quadrupedal locomotion. By means of the estimation of the body mass of the type of the species Megatherium americanum , and using the published tracks, different mechanical parameters, such as speed, Froude number, indicators of athletic ability and bending and resistance moments of the vertebral column were calculated in both bipedal and quadrupedal conditions. Results on leg parameters are not conclusive as to the kind of locomotion to which Megatherium sp. was better adapted, but the calculations on the moments of resistance of the vertebral column and on the bending moment at breaking of the femur seem to indicate that Megatherium sp. presented adaptations to bipedalism. MEGATHERIUM, mammals, legs, vertebral column, locomotion, biomechanics, reconstruction .  相似文献   

5.
6.
Abstract  The genus Menippus is revised for Australia, with six species, three of which are new: M. cynicus Clark, M. darcyi sp. nov. , M. ewani sp. nov. , M. fugitivus (Lea), M. sufi sp. nov. and M. yulensis (Jacoby) comb. nov. (from Diorhabda Weise). Menippus yulensis was described from New Guinea. This species and M. darcyi were formerly confused in Australia with M. fugitivus , which is now considered endemic to Lord Howe Island. The species formerly considered M. fugitivus and protected under the Threatened Species Conservation Act, New South Wales, is now named M. darcyi . A key is provided for the Australian species of Menippus and a lectotype designated for M. yulensis . The composition of Menippus is discussed and three non-Australian species are transferred to this genus: M. inconspicua (Jacoby) comb. nov. (from Diorhabda Weise); M. laterimaculata (Jacoby) comb. nov. ; and M. marginipennis (Jacoby) comb. nov. (from Galerucella Crotch). A revised checklist of Menippus species is given. The recorded foodplants of Menippus are species of Celtis (Ulmaceae).  相似文献   

7.
The spider genus Metabus (Tetragnathidae) previously included nine species: the type M. gravidus O. P.-Cambridge, 1899 – junior synonym of Leucauge ocellata (Keyserling) – from Central America and eight species from Chile. In this paper, the classification of the Metabus species-complex is revised, and two new genera, with three new species and five new combinations, are described. Allende gen. nov. is created for four Chilean species not congeneric with the type of Metabus : the type A. puyehuensis sp. nov. , A. patagiatus (Simon) comb. nov. , A. nigrohumeralis (F. O. P.-Cambridge) comb. nov. and A. longipes (Nicolet) comb. nov. Further additions to the Chilean fauna are under the new genus Mollemeta gen. nov. – created for M. edwardsi (Simon) comb. nov. – and three new species of Chrysometa : C. acinosa sp. nov. , C. levii sp. nov. and C. maitae sp. nov. Metabus now includes four species: M. ocellatus (Keyserling) comb. nov. , M. debilis (O. P.-Cambridge) comb. nov. , M. ebanoverde sp. nov. and M. conacyt sp. nov. All of these species were included in a phylogenetic analysis of 38 tetragnathid and 12 orbicularian outgroup terminals scored for 105 morphological and behavioural characters. The results suggest that Metabus as previously circumscribed is polyphyletic. The phylogenetic relationships within tetragnathids are briefly discussed. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 , 285–335.  相似文献   

8.
Two new species of Multiclavula are described from Rwanda: M. akagerae , with a thallus consisting of turgescent glomerules, and M. rugaramae , with a thallus composed of flattened, rounded, marginate, and dispersed squamules. They grow on soil in frequently burned savannas or on lateritic soils in eastern Rwanda. The genus Lepidostroma should probably be reduced into synonymy with Multiclavula .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 457–465.  相似文献   

9.
A comprehensive taxonomic revision of the genus Maesa Forssk. (Maesaceae) occurring in the Philippines is presented for the first time. Thirteen species are recognized, including a newly described species, M. stonei , which is most similar to M. reflexa . Several previously used names are reduced to synonymy, including M. pachyphylla and M. undulata (both reduced to synonymy with M. cumingii ), and M. elmeri , M. laxa and M. ramosii (all reduced to synonymy with M. indica ). Extensive lectotypification has been necessary due to the destruction of many type specimens, particularly those of C. Mez (in B) and E. D. Merrill (in PNH). The conservation status of each species is determined using the IUCN red list categories and criteria.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 17–43.  相似文献   

10.
A new species of the basal mosasaurid Halisaurus from the Late Cretaceous (Late Maastrichtian) of the Oulad Abdoun Phosphate Basin of Morocco is described on the basis of both cranial and postcranial remains. H. arambourgi sp. nov. is characterized by unique features of the nares, frontal, parietal, girdle and limb bones. A phylogenetical analysis supports the monophyletic status of Halisaurus ; H. platyspondylus (Maastrichtian, New Jersey), H. ortliebi (Maastrichtian, Belgium) and H. arambourgi form an unresolved polytomy. This study does not support the attribution of ' Halisaurus ' sternbergii (Santonian, Kansas) to Halisaurus nor to any known genus. A new genus, Eonatator , is proposed for the reception of this species, Eonatator sternbergii comb. nov. The new taxon Halisaurinae ( Halisaurus  +  Eonatator ) is the sister-group of more advanced mosasaurids (Natantia). Halisaurines are defined by the shape of the lateral premaxilla–maxilla suture; an oblique contact plane between the parietal and the supratemporal; a preaxial ridge present on the distal two-thirds of the radius length; and tibia and fibula long and slender with slightly expanded extremities.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 447–472.  相似文献   

11.
12.
Abstract:  A new species of Moeritherium (Proboscidea, Mammalia), M. chehbeurameuri sp. nov., is described from remains discovered in the early late Eocene locality of Bir El Ater, Algeria. Although mainly represented by isolated teeth, it shows distinct synapomorphies which justify its attribution to the genus Moeritherium , together with exclusive features that led to the creation of the new species. The main characteristic of this new taxon is the almost complete lophodonty shown by its molars, while Moeritherium is commonly regarded as a bunolophodont to bunodont taxon. In addition to this lophodonty, this new taxon shows anatomical features as yet unknown for the genus, but often met within lophodont early proboscidean taxa such as Phosphatherium escuilliei and Numidotherium koholense . Although a revision of the whole genus Moeritherium is outside the scope of this paper, the main controversies and discussion about the definition of species within the genus Moeritherium are discussed. The surprising lophodonty of M. chehbeurameuri , together with its small size, its early late Eocene age and the weak molarization of its P3 support the hypothesis of a lophodont hypothetical ancestor for moeritheres, and therefore strengthen the growing hypothesis of a lophodont dental ancestral morphotype for proboscideans.  相似文献   

13.
Five new species of the family Simuliidae Stegopterna byrrangii Yankovsky, sp. n. and Cnephia chaurensis Yankovsky sp. n., from Taimyr peninsula, Metacnephia olyutorii Yankovsky sp. n. from Kamchatka, Metacnephia karakechensis Yankovsky sp. n. and Montisimulium sonkulense Yankovsky sp. n. from Kirghizia, are described. Stegopterna byrrangii differs from related species: in male--from all known species of the genus by peculiar form of apical end of gonostyles, when apical spine is approximately parallel to inner surface of gonostyle; in female--from all known species of the genus by very long genital lobes (their length twice more than width), from S. longicoxa Rubzov, 1971 and S. duodecimata (Rubzov, 1940) by long stem of genital fork, absence of anterolateral sclerotized projections of branches of genital fork; in pupa--from all known species of the genus by number of filaments of respiratory organ (14-16, when in other species no more than 12). Cnephia chaurensis differs from related species: in male--from C. intermedia Rubzov, 1956 and C. toptchievi Yankovsky, 1996 by absence of medial projection or ridge of gonosternum, from C. intermedia by widened body of gonosternum, from C. toptchievi by ridge on gonocoxites and wide triangular projections near base of arms of gonosternum; in female--from C. intermedia by sclerotized finger-like anterolateral projections of branches of genital fork, subdivision of branches into two lobes, wide flat apical end of stem of genital fork. Metacnephia karakechensis differs from related species: in male--from M. subalpina (Rubzov, 1956) by form of gonostyles, absence of triangular medial projection of gonosternum, short widened gonofurca and more number of spines in parameres, from M. kirjanovae (Rubzov, 1956) and M. slepjani (Rubzov, 1967) by triangular body of gonosternum, widened gonostyles, more number of spines in parameres; in larva--from M. subalpina by more number of rays of primary fan of premandibles, less number of ridges of hooks in posterior attachment organ, from M. kirjanovae by short thick antennae; in pupa--from M. subalpina by character of divergence of upper thick filaments of respiratory organ, from M. kirjanovae by presence of thick filaments of the organ. Metacnephia olyutorii differs from related species: in female--from M. larunae Worobez, 1984 and M. aldanica Worobez, 1987 by thick sclerotized anterolateral projections of branches of genital fork, from M. taimyrica Patrusheva, 1976 by 1-ended (not 3-ended) anterolateral projections of branches of genital fork, large (not shortened) anal lobes, from M. crassifistula (Rubzov, 1956) by very long stem of genital fork. Montisimulium sonkulense differs from related species: in male--from M. brachystylum (Rubzov, 1976) by more prolonged gonostyles, less number of spines of parameres, from M. ocreastylum (Rubzov, 1956) by form of gonostyles, from M. odontostylum (Rubzov, 1947) by more number of spines of parameres; in female--from M. brachystylum and M. odontostylum by stricktly developed posteromedial projections of branches of genital fork, from species having posteromedical projections of branches of genital fork--from M. (ABSTRACT TRUNCATED)  相似文献   

14.
A new species of the thermophylic Tethyan relict prawn Typhlatya is described from two anchialine caves near Perpignan (southern France). The new species is closely related to a congener known only from a freshwater cave at Castellón (eastern Spain), about 400 km to the south-west, differing apparently only in the size and shape of the rostrum and the armature of the dactylus of the fifth pereiopod. Based on palaeogeographical evidence and assuming a sister-group relationship between both species, we suggest that their common ancestor could not be older than early Pliocene in age, and that it was already a stygobiont taxon adapted to live in shallow-water marine crevicular habitats. This ancestor would have vanished from the western Mediterranean after the cooling associated with the onset of northern Hemisphere glaciation, about 3 Mya, as documented for other Mediterranean marine taxa. Indeed, the genus is completely stygobiont and does not occur in fluvial environments. The Pyrenees represent a watershed boundary that eliminates the possibility of the derivation of one species from the other by active dispersal after establishment in continental waters.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 387–414.  相似文献   

15.
Calyptraeid gastropods are well know for the taxonomic difficulties caused by their simple, phenotypically variable shells. In this paper I demonstrate that what was previously considered to be a single species, Crepidula aculeata , is an ancient (3–15 Myr) cryptic species complex made up of at least eight species, and that this group should be placed in the genus Bostrycapulus . Despite the difficulty in finding diagnostic adult shell and anatomical features upon which species can be unambiguously identified, DNA sequences, protoconch morphology, embryonic morphology and developmental characters clearly differentiate these eight species. A single species with direct development and nurse eggs is present in the South Atlantic, and a species with planktotrophic development occurs in the equatorial Pacific. The species from Japan, Australia, Florida, the Pacific coasts of Mexico and Central America, and the Cape Verde Islands all have direct development. Most of these species are separated by > 15% divergence in COI sequence data. The fossil record of Bostrycapulus goes back to the Miocene, which agrees with genetic estimates of divergences within the genus ranging from 3 to 15 Mya. Surprisingly, these ancient species differ only slightly in morphology from each other and genetic differentiation does not correlate with geographical distance. I revise the genus Bostrycapulus on the basis of differences in adult morphology, embryonic morphology, mode of development, protoconch morphology, and DNA sequence data. I also describe four new species ( B. pritzkeri sp. nov., B. odites sp. nov., B. latebrus sp. nov. and B. urraca sp. nov. ) and remove three others ( B. gravispinosus , B. calyptraeformis , and B.  cf. tegulicius ) from synonymy with B. aculeatus .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 75−101.  相似文献   

16.
The genus Melaloncha Brues is defined and groundplan character states established based on outgroup comparison with Phalacrotophora Enderlein and Melittophora Brues. Major groupings within Melaloncha are recognized, and two subgenera are established: Udamochiras Enderlein (type species M. colossia (Enderlein)) and Melaloncha s.s. (type species M. pulchella Brues). Subgenus Udamochiras is revised and 42 species are recognized, including the following 33 new to science: M. anaticula , M. angustifrons , M. apicula , M. aprica , M. basella , M. biseta , M. brevicarina , M. carinata , M. compressicauda , M. exigua , M. falcata , M. flavilata , M. hamata , M. hansoni , M. horologia , M. individa , M. lobata , M. maculifrons , M. parkeri , M. paxilla , M. premordica , M. rhampha , M. rhypopoda , M. rostrata , M. sinuosa , M. spatula , M. spicula , M. triangularis , M. trua , M. valeria , M. vargasi , M. villosa , M. woodi . Melaloncha simillima Borgmeier is removed from synonymy with M. piliapex Borgmeier and reinstated as a separate species; lectotypes are designated for both.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 1−42  相似文献   

17.
18.
We describe a striking new species of the lungless salamander family Plethodontidae from the Appalachian foothills of northern Georgia, USA. This miniature species, c . 25–26 mm (adult standard length), is so distinctive genetically and morphologically that we erect a new genus, the first new genus of amphibian described from the US in nearly 50 years. It is unique among plethodontids from eastern North America in displaying sexual colour dimorphism. Although certain miniaturized plethodontids exhibit a reduced number (four) of digits on the pes, this species possesses a full complement of five toes. A plethodontid phylogeny derived from mitochondrial and nuclear DNA sequences places it in the tribe Spelerpini as the sister taxon to Eurycea . Genetic divergence between the new species and Eurycea for the nuclear gene Rag -1 (4.7%) is among the higher levels observed between long-established spelerpine genera (2.6–5.3%). This new form appears to be rare and is of immediate conservation concern.  相似文献   

19.
Abstract:  Four genera of extinct ringtail possums have been reported from Australian Oligocene to Miocene sediments since 1987. The genus Marlu was described from two species, M. kutjamarpensis and M. praecursor (Woodburne, Tedford and Archer), from the Miocene Kutjamarpu Local Fauna (Leaf Locality) and late Oligocene Wadikali Local Fauna respectively, of northern South Australia. New fossil material referable to this genus has been collected from the Leaf Locality and the Oligocene to Miocene Riversleigh World Heritage Area in northwest Queensland. Three new species, Marlu karya sp. nov. from middle Miocene Riversleigh local faunas and Marlu syke sp. nov. and Marlu ampelos sp. nov. from the Leaf Locality as well as early to middle Miocene Riversleigh local faunas are described. A revision and rediagnosis of the genus and published species are made following the re-examination of referred material in conjunction with the new material. Marlu is characterized by simple dentition and synapomorphies with extant pseudocheirids such as a conjoined postmetacristid and preentocristid on m1 and the loss of the entostylid ridge. New material from middle Miocene Riversleigh deposits has been referred to M. kutjamarpensis , extending the known distribution and age of that species. Re-examination of M. praecursor has revealed the presence of a small m1 entostylid ridge, contributing further to differences between M. praecursor and all other Marlu species and raising the possibility that Marlu is paraphyletic. The new material does not contradict a sister group relationship between ' Marlu ' (excluding M. praecursor ) and the Pliocene–Pleistocene genus Pseudokoala. Homology of the pseudocheirid m1 protostylid identified in species of Paljara , Pildra and Marlu with that observed in extant species is reconsidered. The 'protostylid' of the extinct genera is herein described as the buccal stylid.  相似文献   

20.
The taxonomy of the New World species of the genus Trichadenotecnum is revised. A total of 44 species, including 29 new species, were treated. These species are classified into 12 monophyletic species groups, eight of them newly proposed here. Two species previously assigned to Trichadenotecnum , T. pichincha New & Thornton and T. sylvaticum Turner, are recognized as not belonging to this genus. Phylogenetic relationships among 16 previously and presently proposed species groups are estimated based on a data matrix of 58 morphological characters. Trees from these analyses support monophyly of Trichadenotecnum and the proposed species groups. The New World species were divided into three major clades. Based on the phylogenetic hypothesis and distributional pattern of the species groups, the biogeographical history of the New World Trichadenotecnum is discussed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 651–723.  相似文献   

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