Cenozoic Vertebrate Research Articles

Small Mammal Trackways from the Neogene Vinchina Basin, Argentina: Insights into Xenarthra (Dasypodidae), Notoungulata (Typotheria), and Rodentia (Caviomorpha)

—Neogene deposits of northwestern Argentina host an outstanding ichnological record of the Cenozoic vertebrate faunas developed within a context of continental isolation in South America. The Vinchina (Middle to Late Miocene) and Toro Negro (Late Miocene to Early Pleistocene) formations, at La Rioja Province, have enhanced our understanding of these faunas for over the last 15 years. This contribution aims to explore and report the diversity of trackmakers responsible for five small mammal trackways. Four ichnospecies have been identified, of which three are new. Pichipoda igen. nov. has didactyl to monodactyl manus and tridactyl mesaxonic pes impressions with robust digits with blunt tips. Pichipoda manganae igen. nov. isp. nov. has didactyl manus and is the largest ichnospecies and Pichipoda vizcainoi igen. nov. isp. nov. has almost monodactyl manus impressions. They are interpreted as produced by armadillos (Xenartha: Dasypodidae), specifically P. vizcainoi most likely by tolypeutines (Tolypeutinae), with a trunk length of 21-23.5 cm, and an inferred body mass of 14.7 kg and 8.64 kg, respectively. Fossil armadillo footprints were unknown until now. Tridactylonicha marsicanae igen. nov. isp. nov., has tridactyl to didactyl paraxonic manus and tridactyl mesaxonic pes impression with long, slender, and pointed tips, they are interpreted as produced by hegetotheriids (Notoungulata: Typotheria: Hegetotheriidae) with a body mass of 3.7 kg, and a trunk length of 14 cm. Finally, it is recognized an extensive and complete trackway assigned to Dolichotichnus marae, with tetradactyl paraxonic manus and tridactyl mesaxonic pes impressions, representing an animal of 10.3 kg and a trunk length of 15 cm, is most likely produced by dolichotines (Rodentia: Caviomorpha: Caviidae). These findings provide new records of footprints previously unknown of small mammals, complementing our knowledge of the anatomical traits of small xenarthrans and some of the smallest extinct native ungulates.

Basal Primatomorpha colonized Ellesmere Island (Arctic Canada) during the hyperthermal conditions of the early Eocene climatic optimum.

Anthropogenically induced warming is transforming Arctic ecosystems across a geologically short timescale, but earlier episodes of Earth history provide insights on the nature and limitations of biotic change in a rapidly warming Arctic. Late early Eocene strata (~52 Ma) of the Margaret Formation on Ellesmere Island, Nunavut, Canada sample a warm temperate ecosystem with a polar light regime situated at ~77°N paleolatitude. This extinct boreal ecosystem hosted a diversity of early Cenozoic vertebrates, including thermophilic taxa such as crocodilians and tapiroid perissodactyls. Here we describe two new species of the early primatomorphan Ignacius from Ellesmere, which are by far the northernmost known records for Paleogene Primatomorpha. Ellesmere species of Ignacius are sister taxa, indicating a single colonization of Ellesmere from farther south in North America coincident with the onset of the hyperthermal Early Eocene Climatic Optimum (EECO). The Ellesmere Ignacius clade differs from closely related taxa inhabiting mid-latitudes in being larger (thereby conforming to Bergmann's rule) and having modified dentition and muscles of mastication for a dietary regime emphasizing hard objects, possibly reflecting an increased reliance on fallback foods during long polar winters. The late early Eocene mammalian fauna of Ellesmere indicates that its unique paleoenvironment rendered it uninhabitable to some clades, including euprimates, while selected taxa were able to adapt to its challenging conditions and diversify.

Should Neglected Fossils Be Considered as Geoheritage? The Case of Cenozoic Vertebrates Found in the Province of León (Spain)

Should Neglected Fossils Be Considered as Geoheritage? The Case of Cenozoic Vertebrates Found in the Province of León (Spain)

Vertebrate footprints from the Agha Jari Formation (late Miocene-Pliocene), Zagros Mountains, and a review of the Cenozoic vertebrate ichnites in the Persian Gulf region

Vertebrate footprints from the Agha Jari Formation (late Miocene-Pliocene), Zagros Mountains, and a review of the Cenozoic vertebrate ichnites in the Persian Gulf region

Anatomy, Relationships, and Paleobiology of Cambaytherium (Mammalia, Perissodactylamorpha, Anthracobunia) from the lower Eocene of western India

ABSTRACT The anatomy of Cambaytherium, a primitive, perissodactyl-like mammal from the lower Eocene Cambay Shale Formation of Gujarat, India, is described in detail on the basis of more than 350 specimens that represent almost the entire dentition and the skeleton. Cambaytherium combines plesiomorphic traits typical of archaic ungulates such as phenacodontids with derived traits characteristic of early perissodactyls. Cambaytherium was a subcursorial animal better adapted for running than phenacodontids but less specialized than early perissodactyls. The cheek teeth are bunodont with large upper molar conules, not lophodont as in early perissodactyls; like perissodactyls, however, the lower molars have twinned metaconids and m3 has an extended hypoconulid lobe. A steep wear gradient with heavy wear in the middle of the tooth row suggests an abrasive herbivorous diet. Three species of Cambaytherium are recognized: C. thewissi (∼23 kg), C. gracilis (∼10 kg), and C. marinus (∼99 kg). Body masses were estimated from tooth size and long bone dimensions. Biostratigraphic and isotopic evidence indicates an age of ca. 54.5 Ma for the Cambay Shale vertebrate fauna, the oldest Cenozoic continental vertebrate assemblage from India, near or prior to the initial collision with Asia. Cambaytheriidae (also including Nakusia and Perissobune) and Anthracobunidae are sister taxa, constituting the clade Anthracobunia, which is sister to Perissodactyla. We unite them in a new higher taxon, Perissodactylamorpha. The antiquity and occurrence of Cambaytherium—the most primitive known perissodactylamorph—in India near or before its collision with Asia suggest that Perissodactyla evolved during the Paleocene on the Indian Plate or in peripheral areas of southern or southwestern Asia.

Cenozoic vertebrate biostratigraphy of South Carolina, U.S.A., and additions to the fauna

Study of vertebrate fossils from the South Carolina Coastal Plain played a significant role in the early history of vertebrate paleontology as a scientific discipline in North America. However, a clear understanding of the state’s vertebrate biostratigraphy has been greatly hindered by the paucity of well-exposed fossil-bearing stratigraphic sections and a complicated subsurface stratigraphy. Most units, particularly those of Neogene and Quaternary age, exist as thin veneers of marine or estuarine sediments that typically occur as infilled topographic lows or erosional remnants as determined primarily from borehole stratigraphy. Hence, lateral continuity can be difficult to confirm over broad geographic areas often resulting inconfusion insofar as vertebrate fossil provenance is concerned. The evaluation of vertebrate fossils from the South Carolina Coastal Plain presented here, and of the geologic units from which they originated, or are thought to have originated, results in the first modern biostratigraphic framework for the known Cenozoic record of the state. Results provide (1) updated correlations of many units to the most recent, astronomically-tuned marine oxygen isotope stages; (2) the first viverravid from the Atlantic Coastal Plain, Didymictis proteus; (3) new information on the timing of certain Neotropical immigrants into the Southeast during the Great American Biotic Interchange, including the oldest record of Erethizon in this region and the oldest records of capybara in the USA; (4) the possible oldest record of the microtine rodent Allophaiomys pliocaenicus in the USA; (5) new details on the unit of origin for the type specimen of the archaeocete Dorudon serratus; and (6) new details on the ontogeny of the early odontocete Agorophius pygmaeus. New taxonomic records from South Carolina include Glyptotherium texanum, Holmesina floridanus, Ondatra idahoensis, Erethizon ?bathygnathum, Leopardus amnicola, Miracinonyx ?trumani, Canis lepophagus, Canis latrans, Phocanella pumila, Callophoca obscura, Monatherium sp., Anchippus texanus, Subhyracodon mitis, Aphelops ?malacorhinus, Teleoceras ?guymonense, and Perchoerus sp. New specimens of previously recorded taxa are also noted.

Systematic Revision of the Vizcachas (Rodentia, Caviomorpha, Chinchillidae) from the Chapadmalal Formation, Late Pliocene of Buenos Aires Province, Argentina

Abstract. Lagostomine rodents (Caviomorpha, Chinchillidae) are very abundant in late Cenozoic vertebrate associations of the Pampean area but the study of their systematics has been mostly limited to a handful of works from the late 19th Century and early 20th Century. Although seven species of Lagostomus were described for the Chapadmalal Formation (late Pliocene; Buenos Aires Province, Argentina), the holotypes of these species do not present precise stratigraphic provenance and have not been studied since their original description. This study of lagostomines from the Chapadmalal Formation with precise stratigraphic provenance gives way to the recognition of at least three species: Lagostomus incisus, L. compressidens and L. euplasius. The comparative study of the holotypes of the previously recognized species in this unit indicates that ‘Viscaccia indefinita’ is a junior synonym of L. compressidens while ‘V. loberiaense’, ‘V. definita’ and ‘V. chapalmalense’ are junior synonyms of L. euplasius. The va...

A vertebrate microsite from a marine-terrestrial transition in the Foremost Formation (Campanian) of Alberta, Canada, and the use of faunal assemblage data as a paleoenvironmental indicator

Vertebrate microfossil assemblages contain abundant fossil material of small and large bodied animals recruited from the local paleocommunity that can provide important information for reconstructing regional paleoecology. The Foremost Formation is the oldest unit of the Belly River Group, and records the transition from the fully marine shales of the Pakowki Formation to the non-marine strata of the relatively well-sampled Oldman and Dinosaur Park formations. Although the Foremost Formation has relatively limited exposure and vertebrate fossil material is not abundant, it does contain some important early records of major vertebrate clades from Laramidia (e.g. ceratopsids, pachycephalosaurids).Here we document a new microfossil locality from the upper part of the formation that shows a transitional assemblage containing an abundance of terrestrial forms such as dinosaurs and other sauropsids, while still showing considerable marine influence. The proportion of marine taxa at this site is reduced relative to most sites known from the Foremost Formation, though much higher than more terrestrial sites of the overlying Oldman Formation. In addition to filling a gap in our understanding of this paleoenvironmental transition, this new site preserves two particularly significant specimens: a large, complete, cephalic spine of the hybodont shark Hybodus, and jaw fragments from the ratfish Elasmodus. This represents the first known complete cephalic spine of a hybodont shark from the Cretaceous of Alberta. The ratfish jaw fragments represent the first published record of this group from the Foremost Formation, further increasing our knowledge of chondrichthyan diversity in the Western Interior Seaway. Comparisons of this site to other microsites from the Campanian of Alberta demonstrate the utility of certain key groups, such as lissamphibians and chondrichthyans, in determining paleoenvironments from Mesozoic and Cenozoic vertebrate microsite assemblage data.

The Cenozoic Vertebrate Fossils from the Nepal Himalaya: A Review

The last four decades have been fruitful for recording the Cenozoic vertebrate fossils in the Nepal Himalaya. This information is very important to understand the evolution of vertebrate fauna as well as the climate in which they were living during and after the collision of the Indian subcontinent to Eurasian continent. This paper gives a review of the landmark contribution which has been made by different authors on this aspect.J. Nat. Hist. Mus. Vol. 27, 2013: 120-131

Measuring Earth-Life Transitions: Ecometric Analysis of Functional Traits from Late Cenozoic Vertebrates

Ecometrics is the quantitative study of functional traits at the community level, and the environmental sorting of those traits at regional and continental scales. Functional traits are properties of organisms that have a direct physical or physiological relationship to an underlying quality of the environment, which in turn has indirect links to broader environmental factors such as temperature, precipitation, elevation, atmospheric composition, or sea level. When the same environmental factor affects the performance of many taxa, ecometric sorting is the result. Ecometric patterns in trait distributions across space and through time are therefore a product of biogeographic sorting, evolution, and extinction driven by changes in Earth systems. We review concepts associated with ecometrics, with examples that illustrate how trait-based approaches differ from taxon-based methods, how ecometrics can be used to study Earth-life transitions in the fossil record, and how ecometrics can be used to compare Earth-life transitions that differ in temporal or geographic scale. This paper focuses on the climatic and biome changes of the Great Plains of North America during the Miocene, when grasslands came to be the dominant vegetation type, and of the Anthropocene of the American Midwest, which saw extensive landscape changes in the nineteenth century.

Review of Japanese Cenozoic (Miocene–Modern) Vertebrate Tracks

One hundred and seventy three Cenozoic vertebrate track sites from Miocene to 1600 A.D have been reported in Japan. Three ichnofaunas can be recognized: a perissodactyl and artiodactyl ichnofauna in the Miocene, an artiodactyl and proboscidean ichnofauna in the Plio-Pleistocene, and human ichnofauna from about 900–800 B.C. to about 1400–1600 A.D. Track data indicate that a predominance of large vertebrates in fluvio-lacustrine environment in lowland changed from perissodactyls to proboscidean through Miocene to Plio-Pleistocene, and ancient people then occupied lowlands instead of large animals. Pes length of proboscidean tracks revealed temporal variation, and the relationship between proboscidean body sizes and tracks was observed. The Cenozoic Japanese proboscidean trackways can be distinguished on the basis of trackway width, as narrow- and wide-gauge, but the difference between of those narrow- and wide-gauge trackways probably indicates generic level differences. The Cenozoic Japanese bird tracks can be identified as four types: ?crane (Family Gruidae?), ?heron (Family Ardeidae?), ?stork (Family Ciconiidae?), and ?shorebird tracks.

Oligocene-Miocene Mammalian Fossils from Hongyazi Basin and Its Bearing on Tectonics of Danghe Nanshan in Northern Tibetan Plateau

A shortage of Cenozoic vertebrate fossils in the Tibetan Plateau has been an obstacle in our understanding of biological evolution in response to changes in tectonism, topography, and environment. This is especially true for Paleogene records, so far known by only two sites along the northern rim of the Plateau. We report a Hongyazi Basin in northern Tibetan Plateau that produces at least three mammalian faunas that span Oligocene through late Miocene. Located at the foothills of the Danghe Nanshan and presently connected to the northern margin of the Suganhu Basin through the Greater Haltang River, the intermountain basin is controlled by the tectonics of the Danghe Nanshan to the north and Chahan’ebotu Mountain to the south, making the basin sediments well suited for inferring the evolutionary history of these two mountain ranges. At the bottom of the local section, the Oligocene Haltang Fauna is best compared to the early Oligocene Desmatolagus-Karakoromys decessus assemblage in the Dingdanggou Fauna in Tabenbuluk Basin. The Middle Miocene Ebotu Fauna from the middle Hongyazi section shares many taxa with the late Middle Miocene Tunggur mammal assemblage in Inner Mongolia, such as Heterosminthus orientalis, Megacricetodon sinensis, Democricetodon lindsayi, and Alloptox gobiensis. Toward the top of the section, the Hongyazi Fauna includes late Miocene elements typical of Hipparion faunas of North China. All three faunas are of typical North China-Central Asian characteristics, suggesting a lack of geographic barriers for faunal differentiation through the late Miocene. Sedimentary packages producing these faunas are arrayed from north to south in progressively younger strata, consistent with a compressive regime to accommodate shortening between Danghe Nanshan and Chahan’ebotu Mountain by thrust faults and folds. With additional constraints from vertebrate fossils along the northern flanks of the Danghe Nanshan, an eastward propagation of the Danghe Nanshan is postulated.

Description and interpretation of Cenozoic vertebrate ichnofossils in Rio Grande do Sul State, Brazil

Description and interpretation of Cenozoic vertebrate ichnofossils in Rio Grande do Sul State, Brazil

Geological Features for Geotourism in the Western Part of Sahand Volcano, NW Iran

The NW part of Iran is particularly rich in geological features and formations defining its geological heritage, and attracts tourists worldwide. Most of NW Iran is located in a volcanic arc zone of Cenozoic age, including the Quaternary. The subduction of the Neo-Tethys ocean floor beneath the central block of Iran during the Cenozoic resulted in the formation of this zone. This geological setting has provided NW Iran with diverse natural geological features of high significance. Some of the main geological features include the Sahand Volcano, the Urmia Lake, salt deposits, travertine deposits, springs, limestone caves, tectonic structures and Cenozoic vertebrate fossils. This exceptional geodiversity together with the rich cultural heritage provides a valuable base for geotourism and geopark development, which is needed to diversify local economy and strengthen rural development. However, for tourism to be successful and sustainable, the planning and management must be based on up-to-date knowledge and understanding of the tourism resources, as well as on a holistic overview of the many facets of the geological and cultural heritage.

Cenozoic Vertebrates of the Americas: Papers to Honor S. David Webb

Cenozoic Vertebrates of the Americas: Papers to Honor S. David Webb

Late Cenozoic vertebrates from Honduras and El Salvador

ABSTRACT The subhumid Pacific slopes of El Salvador and Honduras contain a valuable record of late Cenozoic terrestrial vertebrates. Vast ignimbrite flows, mainly of mid-Miocene age, and subsequent block-faulting and basin-filling provide a substantial sequence of late Cenozoic tuffaceous sediments. This paper discusses the geological setting and faunal content of six local faunas ranging from the late Miocene through the late Pleistocene. Many other more limited late Pleistocene sites are known throughout Honduras and El Salvador. The late Miocene fauna includes no families not already known from North America at temperate latitudes, but does indicate an endemic turtle genus, Rhinoclemmys, and endemic mammal species Pliohippus hondurensis and Rhynchotherium blicki, and a much earlier record of brevirostrine proboscideans than in temperate North America. Although no Pliocene faunas are known, substantial numbers of previously South American taxa appear in the early Pleistocene. By the late Pleistocene, in...

Brief account of Cenozoic vertebrate paleontology in Middle America

Brief account of Cenozoic vertebrate paleontology in Middle America

Cenozoic Vertebrate Localities and Faunas in Arizona

Cenozoic deposits in many areas of Arizona. Few of those fossil vertebrates have been adequately studied and described. Our purpose is to record the occurrence of Cenozoic vertebrates in Arizona. We hope this study will stimulate further research on the complex Cenozoic history of Arizona. Lance (1960) summarized the Cenozoic record of vertebrate localities in Arizona. He noted the absence of fossil vertebrates from the late Cretaceous to the early Miocene. The record is now extended back from the

New Finds of Late Cenozoic Vertebrates*

New Finds of Late Cenozoic Vertebrates^*

The late Cenozoic vertebrate faunas from the San Pedro Valley, Ariz

The late Cenozoic vertebrate faunas from the San Pedro Valley, Ariz