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The first unequivocal remains of medium to large-sized mustelids from the middle Miocene Halamagai and Kekemaideng formations have been found in the Ulungur River area, Xinjiang, northwestern China. These new fossils are referred to the hypercarnivorous mustelid Hoplictis Ginsburg, 1961 and denote the first record of the genus in East Asia. We define Hoplictis baihu n. sp., for the mustelid from Tieersihabahe (Halamagai Fm.), which represents the smallest species of the genus. This primitive form is closer to H. florancei and H. noueli than to H. anatolicus and later, larger and more derived Hoplictis spp., from Europe and North America. A large toothless mandible from Duolebulejin (Kekemaiden Fm.) is assigned to Hoplictis cf. helbingi, and it presumably might represent the first record of H. helbingi outside Western Europe. The systematic position of Hoplicitis in relation to Ischyrictis with which it is similar is clarified. The occurrence in East Asia of two species of Hoplictis greatly expands the known distribution and diversity of the genus, and supports a Palaearctic Neogene dispersal event of carnivorans between Europe and Asia during the late Shanwangian–early Tunggurian equivalent to MN5–6 in Europe, and indication of another dispersal event from Europe to North America, through Northwest China during the late Tunggurian, equivalent to MN7–8 in Europe., Chinese Academy of Sciences, National Natural Science Foundation of China, DST-NFR Centre of Excellence in Palaeosciences, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Triassic Period (~252–201.5 Ma) saw a transformative radiation and reorganization of continental tetrapod diversity following the end-Permian Extinction, including an assemblage of diverse forms that do not survive the end-Triassic (herein termed the 'endemic Triassic fauna', =ETF), as well as the earliest fossil representatives of all major modern tetrapod groups (herein termed the 'Living [Triassic to Recent] Fauna', =LTF; i.e. Salientia, Caudata, Gymnophiona, Mammaliaformes, Squamata, Rhynchocephalia, Testudinata, Crocodylomorpha, and Dinosauria). With few exceptions, only the LTF assemblage survives the end-Triassic Extinction (~201.5 Ma), highlighting the Late Triassic (~227–201.5 Ma) record as essential for understanding this pivotal transition and the evolutionary and ecological origins of post-Triassic non-marine tetrapod faunas, including those of present day. Micro-microvertebrate bonebeds are arguably the best proxy for tracking continental vertebrate biodiversity, however gaps in their Late Triassic record obscure patterns and drivers of evolutionary, ecological, and environmental change during the rise of LTF communities. In my dissertation, I use new data collected from Upper Triassic microvertebrate bonebeds from North America, and particularly the Thunderstorm Ridge site (PFV 456) in Petrified Forest National Park, Arizona, U.S.A, to fill gaps in the evolutionary record of specific groups (e.g., lissamphibians and lepidosaurs), as well as the vertebrate paleocommunity record of Triassic equatorial Pangaea. My first chapter describes and analyzes an assemblage of gymnophionomorph (stem caecilian) bones from PFV 456 which represent the oldest-known caecilian fossils globally. As the oldest caecilian fossils, they provide new support for the dissorophoid temnospondyl affinities of caecilians and other living amphibians, evidence of a step-wise acquisition of caecilian anatomies associated with fossoriality, and evidence of an ancient pattern of equa

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

We report 130 vertebrate fossils preserved as bony elements and the co-occurring assemblage of fish teeth and spines from the lower strata of the Pisco Formation exposed along the western side of the lower Ica Valley (East Pisco Basin, Peru). Geological mapping at 1:10,000 scale reveals that all these fossils originate from the Langhian–Serravallian P0 allomember. In the study area, P0 is up to ∼40 m thick and features a sandy lower portion, reflecting shoreface deposition, that fines upwards into a package of offshore silts. Marine vertebrates only occur in the lower sandy layers and include whales, dolphins, reptiles, birds, and bony and cartilaginous fishes. The reconstructed paleoenvironment is consistent with a warm-water, marginal-marine setting with a strong connection to the open ocean. This work helps to elucidate the rich yet still poorly understood middle Miocene portions of the Pisco Formation, and highlights the need to conserve this outstanding Fossil-Lagerstätte.

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, and outcrop area on Hesperornis occurrences: generalized linear models (GLMs) and occupancy models (an extension of standard GLMs). Results of both model types indicate a decreased probability of Hesperornis presence at elasmosaur-occupied sites and an increased probability of Hesperornis presence with higher paleolatitudes. The negative association between elasmosaurs and Hesperornis in all highest-ranked models, coupled with evidence of similar diets, may indicate food resource competition, but the geographic distributions of both taxa may instead reflect different habitat preferences. The positive impact of paleolatitude may reflect seasonal migrations resulting in large breeding congregations at higher paleolatitudes (based on probable immature specimens), preference for specific environmental conditions or feeding areas (e.g., along oceanographic fronts or upwelling zones), or migration mortality. While Spearman’s correlation test did not identify a western, middle, or eastern WIS preference for Hesperornis, the inclusion of this regional covariate with paleolatitude in the highest-ranked occupancy models may indicate an interaction effect between thes

The Mojave Region preserves a rich and continuous Miocene mammal-fossil record that formed during a time of significant tectonic activity and climate change. We will visit exposures of the Crowder, Cajon Valley, and Barstow formations to look at the evolution of three different sedimentary basins through the middle Miocene. Participants will learn how depositional environments and habitats changed through time in relation to tectonics and climate and how they influenced patterns of mammal diversity and biostratigraphy.

Based on mapping of laterally traceable stratigraphic discontinuities, we propose a high-resolution allostratigraphic scheme for one of the world’s foremost fossil marine vertebrate Lagerstätten: the lower Miocene strata of the Chilcatay Formation exposed along the Ica River near Zamaca, southern Peru. Measured sections combined with 1:10,000 scale mapping of a 24 km2 area provide an overview of the stratal architecture, as well as a general facies framework and interpretation of the various depositional settings. As a whole, the Chilcatay alloformation is bounded by the CE0.1 unconformity at the base and the PE0.0 unconformity at the top. An internal Chilcatay surface, termed CE0.2, splits the alloformation into two distinct allomembers (Ct1 and Ct2). The Ct1 allomember comprises three facies associations recording deposition in shoreface, offshore, and subaqueous delta settings. The Ct2 allomember comprises two facies associations, recording deposition in shoreface and offshore settings. Using these data, we place the rich marine vertebrate assemblage in a precise spatial and stratigraphic framework. The well-diversified vertebrate assemblage is dominated by cetaceans (mostly odontocetes) and sharks (mostly lamniforms and carcharhiniforms); rays, bony fish, and turtles are also present. Taxonomic novelties include the first records of baleen whales, platanistids, and eurhinodelphinids from the Chilcatay Formation.

Following the Permo-Triassic mass extinction, Archosauriformes-the clade that includes crocodylians, birds, and their extinct relatives outside crown Archosauria-rapidly diversified into many distinct lineages, became distributed globally, and, by the Late Triassic, filled a wide array of resource zones. Current scenarios of archosauriform evolution are ambiguous with respect to whether their taxonomic diversification in the Early-Middle Triassic coincided with the initial evolution of dietary specializations that were present by the Late Triassic or if their ecological disparity arose sometime after lineage diversification. Late Triassic archosauriform dietary specialization is recorded by morphological divergence from the plesiomorphic archosauriform tooth condition (laterally-compressed crowns with serrated carinae and a generally triangular lateral profile). Unfortunately, the roots of this diversification are poorly documented, with few known Early-Middle Triassic tooth assemblages, limiting characterizations of morphological diversity during this critical, early period in archosaur evolution. Recent fieldwork (2007-2017) in the Middle Triassic Manda Beds of the Ruhuhu Basin, Tanzania, recovered a tooth assemblage that provides a window into this poorly sampled interval. To investigate the taxonomic composition of that collection, we built a dataset of continuous quantitative and discrete morphological characters based on in situ teeth of known taxonomic status (e.g., Nundasuchus, Parringtonia: N = 65) and a sample of isolated teeth (N = 31). Using crown heights from known taxa to predict tooth base ratio (= base length/width), we created a quantitative morphospace for the tooth assemblage. The majority of isolated, unassigned teeth fall within a region of morphospace shared by several taxa from the Manda Beds (e.g., Nundasuchus, Parringtonia); two isolated teeth fall exclusively within a "Pallisteria" morphospace. A non-metric multidimensional scaling ordinati

The Mojave Region preserves a rich and continuous Miocene mammal-fossil record that formed during a time of significant tectonic activity and climate change. We will visit exposures of the Crowder, Cajon Valley, and Barstow formations to look at the evolution of three different sedimentary basins through the middle Miocene. Participants will learn how depositional environments and habitats changed through time in relation to tectonics and climate and how they influenced patterns of mammal diversity and biostratigraphy.

Based on mapping of laterally traceable stratigraphic discontinuities, we propose a high-resolution allostratigraphic scheme for one of the world’s foremost fossil marine vertebrate Lagerstätten: the lower Miocene strata of the Chilcatay Formation exposed along the Ica River near Zamaca, southern Peru. Measured sections combined with 1:10,000 scale mapping of a 24 km2 area provide an overview of the stratal architecture, as well as a general facies framework and interpretation of the various depositional settings. As a whole, the Chilcatay alloformation is bounded by the CE0.1 unconformity at the base and the PE0.0 unconformity at the top. An internal Chilcatay surface, termed CE0.2, splits the alloformation into two distinct allomembers (Ct1 and Ct2). The Ct1 allomember comprises three facies associations recording deposition in shoreface, offshore, and subaqueous delta settings. The Ct2 allomember comprises two facies associations, recording deposition in shoreface and offshore settings. Using these data, we place the rich marine vertebrate assemblage in a precise spatial and stratigraphic framework. The well-diversified vertebrate assemblage is dominated by cetaceans (mostly odontocetes) and sharks (mostly lamniforms and carcharhiniforms); rays, bony fish, and turtles are also present. Taxonomic novelties include the first records of baleen whales, platanistids, and eurhinodelphinids from the Chilcatay Formation.

Following the Permo-Triassic mass extinction, Archosauriformes-the clade that includes crocodylians, birds, and their extinct relatives outside crown Archosauria-rapidly diversified into many distinct lineages, became distributed globally, and, by the Late Triassic, filled a wide array of resource zones. Current scenarios of archosauriform evolution are ambiguous with respect to whether their taxonomic diversification in the Early-Middle Triassic coincided with the initial evolution of dietary specializations that were present by the Late Triassic or if their ecological disparity arose sometime after lineage diversification. Late Triassic archosauriform dietary specialization is recorded by morphological divergence from the plesiomorphic archosauriform tooth condition (laterally-compressed crowns with serrated carinae and a generally triangular lateral profile). Unfortunately, the roots of this diversification are poorly documented, with few known Early-Middle Triassic tooth assemblages, limiting characterizations of morphological diversity during this critical, early period in archosaur evolution. Recent fieldwork (2007-2017) in the Middle Triassic Manda Beds of the Ruhuhu Basin, Tanzania, recovered a tooth assemblage that provides a window into this poorly sampled interval. To investigate the taxonomic composition of that collection, we built a dataset of continuous quantitative and discrete morphological characters based on in situ teeth of known taxonomic status (e.g., Nundasuchus, Parringtonia: N = 65) and a sample of isolated teeth (N = 31). Using crown heights from known taxa to predict tooth base ratio (= base length/width), we created a quantitative morphospace for the tooth assemblage. The majority of isolated, unassigned teeth fall within a region of morphospace shared by several taxa from the Manda Beds (e.g., Nundasuchus, Parringtonia); two isolated teeth fall exclusively within a "Pallisteria" morphospace. A non-metric multidimensional scaling ordinati

[ES] La carrera científica del Prof. Emiliano Aguirre está directamente unida a la historia reciente del Museo Nacional de Ciencias Naturales. Su contribución y aportación a la Paleontología de Vertebrados durante las últimas décadas ha contribuido al conocimiento del Terciario y Cuaternario de este país y a la formación de varias generaciones de especialistas en Paleontología y Geología. La mayor importancia de estas actividades tiene lugar dentro de la Sección de Paleontología de Vertebrados y Humana del Instituto Lucas Mallada, bajo su dirección. En este período, el incremento de las colecciones del Museo es extraordinario, tanto gracias a la labor desarrollada por el doctor Aguirre como por la del grupo de especialistas formados por él. En este trabajo, se realiza una sucinta revisión de los yacimientos visitados y excavados por él junto con una relación de los fósiles de vertebrados que han quedado depositados en el Museo como producto de su actividad y una breve reseña de las especies o ejemplares más destacados en cada uno de ellos., [EN] The scientific trajectory of Prof. Emiliano Aguirre is strongly linked to the recent history of the Museo Nacional de Ciencias Naturales. During the last few decades he has made an important scientific contribution to Vertebrate Palaeontology of the Tertiary and Quaternary of Spain. Prof. Aguirre has trained several generations of specialists in Palaeontology and Geology. The greatest impact of these activities has been in the Section of Human and Vertebrate Palaeontology of the Instituto Lucas Mallada, while he was director. During this period, the increase of collections of the Museum is extraordinary because of the work carried out both by Prof. Aguirre and by the group of specialists trained by him. In this paper we provide a brief discussion of the sites investigated and excavated by Prof Aguirre, as well as a brief description of the most outstanding fossil vertebrate specimens that have been deposited at the Museo Nacional de Ciencias Naturales as a result of his activities.

Vertebrate fossils have been discovered at several locations in the Bighorn Basin (Wyoming). The Virginia Museum of Natural History's (VMNH) digsite is located in the eastern part of the Bighorn Basin, in the Coyote Basin. Many scientists have worked within these basins trying to describe the stratigraphy. One question specifically asked is where the boundary between the Morrison Fm. (Jurassic) and the Cloverly Fm. (Cretaceous) lies. This new study attempted to show if the current method (Kvale, 1986) of determining the boundary is appropriate. The stratigraphy of the area was examined using Kvale, 1986, Ostrom, 1970, and Moberly, 1960's work in order to see which model was more robust. The fossils in the VMNH digsite were used to supplement the stratigraphic data in determining the age of specific beds. All of Ostrom's units were identified throughout the study area. There is some doubt as to whether the units would be acceptable outside of the Coyote Basin because of laterally discontinuity. Nevertheless, his description of units is satisfactory for the study area, and is more appropriate than other methods. The geologic age of the dinosaurs uncovered in the VMNH quarry is in agreement with the age determined stratigraphically. The VMNH site is below Ostrom's Unit II, which would place it in the Late Jurassic. The determination of the Jurassic/Cretaceous stratigraphic boundary has not been resolved. However, since the Pryor Conglomerate member of the Cloverly Fm. can be identified throughout this area, it is proposed as the Morrison Fm./Cloverly Fm. boundary.

[ES] En este trabajo se analizan las características geológicas y paleontológicas del yacimiento del Pozo de Piedrabuena, Ciudad Real (Castilla-La Mancha, España). Este yacimiento se localiza en materiales transportados por abanicos aluviales de pequeño desarrollo, que colmatan la Depresión de Piedrabuena, rodeada por rocas paleozoicas (cuarcitas y pizarras). A techo de los depósitos hay una expansión de carbonatos palustres. La fauna encontrada ha sido la siguiente: Rodentia indet., cf. Oryctolagus sp., Felix cf. issiodorensis, Hyaena sp., Dicerorhinus cf. etruscus, Cervidae indet. (talla grande), Cervidae indet. (talla pequeña), Gazella borbonica, Hippotraginae indet., que permite situar el yacimiento en el tránsito Rusciniense-Villafranquiense. El análisis paleoambiental muestra la coexistencia de especies de bosque y de zonas abiertas, lo que coincide bien con la estratificación de la vegetación de la zona: rala en las áreas centrales palustres y mucho más desarrollada sobre los abanicos aluviales áridos de los bordes., [EN] This paper deals with a sedimentological palaeontological and paleontological analysis of the Piedrabuena Water Well paleontological site (Ciudad Real, Campo de Calatrava, Castilla-La Mancha, Spain). The fossil mammal remains were accumulated by means of a low efficiency transport fan system, with mass transport mechanisms, which filled the whole of the Piedrabuena Depression: a circular shaped basin sorrounded by Paleozoic rocks (quartzites and shales). Neogene sedimentation evolved towards expansive palustrine carbonate sediments towards the top of the unit. The faunal assemblage composed of Rodentia indet., cf. Oryctolagus sp., Felis cf. issiodorensis, Hyaena sp., Dicerorhinus cf. etruscus, Sus minor, Cervidae indet (big sized), Cervidae Indet. (small sized), Gazella borbonica> and Hippotraginae indet. This fauna is characteristic of the Ruscinian-Villafranchian transition.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

The present contribution is not a unified account, but is a series of essays dealing with some aspects, but is a series of essays dealing with some aspects of evolutionary theory.

https://scholars.fhsu.edu/fort_hays_studies_series/50