摘要:

The holotype of the small sauropod dinosaurAstrodon pusillusLapparent and Zbyszewski, 1957, from the Kimmeridgian (Upper Jurassic) of Portugal is shown to be the remains of a juvenile individual of the stegosaurDacentrurus. The records ofAstrodonfrom the Upper Jurassic of North America and the Lower Cretaceous of Africa are based on material of juvenile sauropods. However, teeth from the Lower Cretaceous of Portugal are correctly referred toAstrodonasA. valdensis(Lydekker). A review is presented of the intercontinental genera that the Late Jurassic and Early Cretaceous faunas of Western Europe shared with faunas of corresponding ages in North America and Africa.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011899

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A large slab of arenaceous siltstone was collected from strata of the Gething Formation (Aptian, Lower Cretaceous) in the Peace River Canyon of northeastern British Columbia, Canada. More than 200 footprints between 2.0 and 4.4 cm in length were found on a single bedding plane within the slab. These were made by a minimum of four individuals that apparently were feeding. The footprints have an average divarication of 113° and a correlated width to length ratio of 1.26, which fall within the range encountered in birds. Divarication between digits II and IV in even the smallest dinosaurs never exceeds 100° on an average per trackway. Other characteristics support the identification of these tracks from the Peace River Canyon as having been made by birds. The new genus and species,Aquatilavipes swiboldae, is the earliest known record of bird footprints, and probably represents a primitive taxon of marsh-dwelling bird.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011900

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

An analysis of the functional morphology of the skull ofTeratomis merriamiindicates that these giant flying birds were predaceous carnivores. This contrasts with prior assumptions that teratorns were scavengers like vultures. The large wingspans of teratorns limited them to savanna habitats. Teratorns probably originated in South America, sharing the dominance of the carnivore adaptive zone in the Tertiary of South America with the better known cursorial carnivorous birds collectively referred to as phorusrhacoids. Their evolution to such large flying birds was most likely directly tied to the progressive development of widespread savanna habitat in South America during the Tertiary. The soaring manner of flight of teratorns may have prevented their dispersal into North America until after the closure of the Central American land bridge. Expansion of savanna habitats in the Americas during Pleistocene glacial periods probably aided this dispersal.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011901

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A new species of thick-knee,Burhinus lucorum, is described from the early Miocene (Sheep Creek Formation, late Hemingfordian) of Nebraska, providing the first Tertiary record of the family. Contrary to the widely held view that thick-knees are necessarily indicative of dry, sparsely vegetated country, the extant species of Burhinidae in fact live in a broad range of habitats. Thus, the use of extinct species of Burhinidae as paleoclimatological indicators is compromised. Evidence from other sources on early Miocene climates is summarized and suggests thatBurhinus lucorummay have inhabited stream-side woodlands.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011902

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Pedinorhis stirpsarcana, an enigmatic new genus and species of emberizine finch, is known from four cave deposits of probable Wisconsinan age in central Puerto Rico. The most distinctive feature of this bird is the broad, flat ridge of the rostrum.Pedinorhisrepresents a group unknown in the Antilles and, although of uncertain affinities, somewhat resembles the mainland generaAtlapetesandPipilo. The disappearance ofPedinorhismay be related to the postglacial loss of arid, savanna-like habitats that caused the extinction, or contraction in range, of many xerophilous vertebrates in the West Indies.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011903

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A nearly complete and partially articulated skeleton ofMesoscalops, a genus of fossorial insectivore hitherto known only by isolated teeth and some bones of the forelimb, is described and compared with other proscalopids, talpids, and chrysochlorids. The skeleton (UWBM 54708) is more complete than that of any proscalopid known to date, and provides a basis for description of the previously unknown vertebral column, ribs, articulated forelimb including the scapula, clavicle, manubrium, pelvis, femur, fibula, astragalus, and metatarsals. UWBM 54708, from the Hemingfordian or Barstovian Deep River Formation, Meagher County, Montana, represents a new species,M. montanensis. The skull ofM. montanensismore closely resembles Whitneyan than late Arikareean proscalopids, suggesting thatMesoscalopswas derived from a Whitneyan form ofProscalops.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011904

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Maxillary fragments, rami, and postcrania referred to the hyaenidChasmaporthetes ossifragusare recorded from two Florida faunas, Santa Fe River (probably late Blancan) and Inglis IA (early Irvingtonian).C. ossifraguswith its reduced premolars, deep mandible, and long blade-like carnassials probably filled the ecologic role of an active predator occupied today by the spotted hyaena,Crocuta. The fore and hind quarters of the hunting hyaena were heavily muscled and its elongate limbs and feet suggest that it was well adapted for cursorial life.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011905

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Kyptoceras amatorumn.g. et sp. is described from the Upper Bone Valley Formation, late Hemphillian (early Pliocene) of Polk County, Florida. In the male skull the forked rostral horn lacks a shaft and the frontal horns are nearly twice as long as those of any other Protoceratidae. Both the rostral and the frontal horns are tilted forward in distinctive fashion. This genus represents a new tribe, Kyptoceratini, which may have originated in subtropical savannas south of the range of the more familiar tribe Synthetoceratini.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011906

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Sixteen mammalian assemblages from the middle Paleocene (Torrejonian) to early Eocene (Wasatchian) of western North America have been studied to determine their species composition and diversity. Torrejonian and Tiffanian faunas are dominated by small mammals of archaic aspect, while larger forms predominate in Clarkforkian assemblages and remain common in the Wasatchian. Both Clarkforkian and Wasatchian faunas are characterized by immigrant taxa, including representatives of more modern groups of mammals.

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011907

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0272-4634    

DOI:10.1080/02724634.1981.10011908

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor