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    Wyświetlanie 1-13 z 13
    Tytuł:
    A morganucodontan mammalia form from the Upper Jurassic Morrison Formation, Utah, USA
    Autorzy:
    Davis, Brian M.
    Jäger, Kai R.K.
    Rougier, Guillermo W.
    Trujillo, Kelli
    Chamberlain, Kevin
    Powiązania:
    https://bibliotekanauki.pl/articles/2216314.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Mammalia
    Morganucodonta
    dentition
    Jurassic
    Morrison Formation
    Opis:
    We describe two skull fragments of a new morganucodontan from the Cisco Mammal Quarry (Upper Jurassic Morrison Formation), preserving portions of the palate and snout in excellent 3D detail as well as the complete upper postcanine dentition. Morganucodontans are best known by isolated elements and relatively complete skulls of several species of Morganucodon from the Lower Jurassic of Wales and China; this group is fundamental to our understanding of the early evolution of mammals. Cifellilestes ciscoensis gen. et sp. nov. possesses derived features of the snout paired with plesiomorphic construction of the molars; the distal premolars are complex and there is an unusually low count (two) of strongly imbricated molars. This character combination expands craniodental variation for the group. We sampled mudstone from the Cisco Mammal Quarry for ash-fall zircon analysis and obtained a date of 151.50 ± 0.28 Ma. This dates the locality to the earliest Tithonian and slightly younger than other major dated mammalbearing localities in the Morrison Formation. Cifellilestes represents one of the youngest members of this group and extends the record of morganucodontans in North America by more than 30 Ma. Morganucodontans are a rare component of Late Jurassic faunas but display surprising dental diversity through variations in a tooth count and cusp morphology of a deeply conserved, generalized mammalian tooth pattern, which was fully established in brasilodontid (non-mammalian) ancestors at least 80 my prior.
    Źródło:
    Acta Palaeontologica Polonica; 2022, 67, 1; 77-93
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Bone Microstructure and Relative Age of the Holotype Specimen of the Diplodocoid Sauropod Dinosaur Suuwassea emilieae
    Autorzy:
    Hedrick, B.P.
    Tumarkin-Deratzian, A.R.
    Dodson, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/945796.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    dinosauria
    sauropoda
    suuwassea
    histology
    jurassic
    morrison formation
    montana
    usa
    Opis:
    We present the first study of bone microstructure in Suuwassea emilieae, a diplodocoid sauropod from the Morrison Formation. Although the holotype of Suuwassea was recently identified as a subadult, bone histology demonstrates that this individual had reached sexual maturity at approximately 75–80% of maximum adult size. The smaller size of the holotype of Suuwassea relative to contemporary sauropods is due to ontogeny rather than a true reflection of adult size. A fully adult individual would have likely been similar in size to a fully adult specimen of Apatosaurus. Suuwassea has a number of plesiomorphic characters that might have been explained by its supposed early ontogenetic status, and would then have called the validity of the taxon into question. However, our demonstration that it was an adult confirms that these features represent retention of plesiomorphic character states or evolutionary reversals in a derived animal. Additionally, the specimen shows extensive cortical drift and secondary osteon formation related to skeletal loading, which is often obscured by complete remodeling of Haversian systems in sauropod taxa. There are substantial differences in the microstructure across the bone, which could make histologic samples not based upon complete cross sections problematic. Suuwassea is one of four currently recognized dicraeosaurid taxa, and this study contributes potential taxonomic characters in sauropod bone microstructure.
    Źródło:
    Acta Palaeontologica Polonica; 2014, 59, 2; 295-304
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new specimen of the basal macronarian Camarasaurus (Dinosauria: Sauropoda) highlights variability and cranial allometry within the genus
    Autorzy:
    Woodruff, D. Cary
    Wilhite, D. Ray
    Larson, Peter L.
    Eads, Matthew
    Powiązania:
    https://bibliotekanauki.pl/articles/2060921.pdf
    Data publikacji:
    2021
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Camarasaurus
    cranial allometry
    Morrison Formation
    allometria czaszki
    formacja Morrisona
    Opis:
    Camarasaurus represents one of the most common dinosaurs from North America, and certainly a contender for one of the most abundantly represented dinosaur taxa worldwide. With numerous specimens ranging the gamut of completeness and maturity, Camarasaurus would theoretically represent a neosauropodian exemplar towards better understanding intra- and interspecific variation, dimorphism, and life history development and strategies. And yet, counterintuitively, its abundance is seemingly a deterrent for active research. Herein we describe a new specimen of Camarasaurus sp. which is most notably known from a nearly complete and articulated skull. While Camarasaurus cranial material is unquestionably the most common sauropod cranial material from North America, our understanding of the total cranial morphology is limited, and largely relies on more limited and historic specimens. In addition to further illuminating the morphology and variation present in Camarasaurus crania, associated post-crania also allow for the first recognition of possible cranial allometry. The identification of this perplexing cranial allometry in several specimens indicates that it is not a singular variation. Though this analysis was not able to source the causal mechanism, factors such as taxonomy, dimorphism, or extreme intra-/intraspecific variation are all possible considerations for future analyses. The recognition of this undocumented cranial allometry further emphasizes that despite being so numerous, there is still vast gaps in our knowledge about Camarasaurus; and this analysis further echoes that the genus is in desperate need of revision.
    Źródło:
    Volumina Jurassica; 2021, 19, 1; 109--130
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fluvial architecture element analysis of the Brushy Basin Member, Morrison Formation, western Colorado, USA
    Autorzy:
    Galli, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077338.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    meandering
    anastomosing
    Morrison Formation
    Kimmeridgian
    Colorado
    meandryzacja
    anastomizacja
    Formacja Morrisona
    Opis:
    The 85-m Brushy Basin Member of the Morrison Formation in western Colorado, USA, comprises dinosaur-bearing sandstones (architectural element CHR and CH), crevasse-splay deposits and minor levee deposits (architectural element CS), mudstones, marlstones, altered ash beds and minor limestones as well as caliche paleosols and noncalcareous paleosols (architectural element FF). Channel sandstones occur at five stratigraphic levels at Trail Through Time (TT), eleven levels at Fruita Paleontological Research Area (FP), and at five levels at Echo Canyon (EC). River-channel sandstones hosted by floodplain mudstones tend to have cut down to resistant caliche paleosols. Depositional facies and architectural element analysis show that the rivers were low gradient, mainly anastomosing, with perennial flow, but seasonal with “flashy” peaks in discharge. Dinosaur bone accumulations are found in some floodplain ponds. Isolated bones are present in anastomosing channel sandstones at TT and in channel sandstone 2 at EC. At FP, major accumulations of bones were rapidly buried in the deep pools at three bends in the meandering river resulting in the formation of channel sandstone 2. There is no evidence for a large lacustrine or playa system at the three localities.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 69--106
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Haplocanthosaurus (Saurischia: Sauropoda) from the lower Morrison Formation (Upper Jurassic) near Snowmass, Colorado
    Autorzy:
    Foster, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077342.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    haplocanthosaurus
    sauropod
    Late Jurassic
    Morrison Formation
    haplokantozaur
    jura późna
    Formacja Morrisona
    Opis:
    A small sauropod dinosaur collected from the Rocky Mountains of central Colorado (north of the Elk Range, Pitkin County) is assigned to the rare genus Haplocanthosaurus. The specimen, MWC 8028, consists of four dorsal centra, five partial ribs, the sacrum, five caudal vertebrae, three chevrons, five partial neural spines and many fragments and is from the lower third of the Upper Jurassic Morrison Formation. The dorsal vertebrae are procamerate, and on the sacral vertebrae the neural arch peduncles are vertically elongate and the neural spines are strongly reclined. The only sauropod from the Morrison Formation that shares these characters is Haplocanthosaurus and based on those characters MWC 8028 is referred to Haplocanthosaurus. This is at most the tenth specimen and the seventh locality for this sauropod, all within the Morrison Formation.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 197--210
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lithostratigraphy of the Jurassic San Rafael Group from Bluff to the Abajo Mountains, southeastern Utah: Stratigraphic relationships of the Bluff Sandstone
    Autorzy:
    Lucas, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077336.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Jurassic
    Utah
    Morrison Formation
    Summerville Formation
    Carmel Formation
    jura
    Formacja Morrisona
    Formacja Summerville
    Formacja Carmel
    Opis:
    Measured sections of Jurassic San Rafael Group strata correlated by lithostratigraphy along an ~60 km transect between Bluff and the Abajo Mountains in southeastern Utah indicate that: (1) the Carmel Formation is continuous and disconformable on the Navajo Sandstone (J-2 unconformity); (2) the Entrada Sandstone (Slick Rock Member) is continuous and conformable on the Carmel; (3) the Summerville Formation is continuous and does not intertongue with the Entrada (its base is the J-2 unconformity); (4) the Bluff Sandstone grades northward into the upper Summerville south of the Abajo Mountains; (5) the Recapture Member of the Bluff is physically continuous with at least part of the Tidwell Member of the Summerville; and (5) the base of the Salt Wash Member of the Morrison Fm. is a pervasive unconformity (J-5) with demonstrable local stratigraphic relief of up to 14 m. These observations counter previous claims of extensive Entrada-Summerville intertonguing in southeastern Utah and do not support recognition of depositional sequence boundaries in the Entrada and Summerville lithosomes. Though Entrada deposition may have been by a wet eolian system, its southeastern Utah outcrops are well to the south/ southeast of any marine and paralic facies with which the Entrada intertongues.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 55--68
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Jurassic vertebrate bromalites of the western United States in the context of the global record
    Autorzy:
    Hunt, A.
    Lucas, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077333.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    bromalite
    consumulite
    evisceralite
    Jurassic
    Morrison Formation
    Sundance Formation
    western USA
    jura
    Formacja Morrisona
    Formacja Sundance
    USA
    Opis:
    The bromalite record of the western United States is quite limited, especially in contrast to the Triassic and Cretaceous records of the same region. Indeed, there are only a handful of well documented vertebrate bromalites from the Jurassic strata of the western USA, including: (1) coprolites from the nonmarine Early Jurassic Glen Canyon Group; (2) consumulites and evisceralites from the Middle Jurassic Todilto and Sundance formations; and (3) consumulites, putative coprolites and pseudobromalites from the nonmarine Upper Jurassic Morrison Formation. Early Jurassic red beds are notably less fossiliferous than those of the Triassic (e.g., contrast the fossil record of the Chinle and Glen Canyon groups). The Middle Jurassic of the region includes several eolianites and sabkha-like deposits representing environments that preserve few bromalites. The Upper Jurassic Morrison Formation contains abundant vertebrate body fossils and many tracks but very few bromalites in contrast to many broadly similar fluvial deposits of Triassic and Cretaceous age in the same region. The global bromalite record also appears to be depauperate in the Jurassic, with a few exceptions such as marine shales and lithographic limestones in Europe (e.g., Lower Jurassic of England, Upper Jurassic Solnhofen Limestone of Bavaria). This relative lack of a global Jurassic bromalite record may in part be more a result of a lack of collection and study. However, the relative lack of nonmarine bromalites is clearly influenced by high sea levels in the Early Jurassic, a paucity of Middle Jurassic nonmarine vertebrate-bearing units and a lack, or lack of recognition of, bromalites in major Upper Jurassic nonmarine vertebrate faunas (e.g., China, Tanzania, Portugal, etc.). In the Western United States there is clearly a need for more detailed examination of known specimens (e.g., putative Morrison coprolites) and a focus on collecting more examples.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 151--158
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A U/Pb age for the Mygatt-Moore Quarry, Upper Jurassic Morrison Formation, Mesa County, Colorado
    Autorzy:
    Trujillo, K.
    Foster, J.
    Hunt-Foster, R.
    Chamberlain, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077340.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Morrison Formation
    U-Pb dating
    CA-TIMS
    dinosaurs
    North American Jurassic
    Formacja Morrisona
    dinozaury
    Opis:
    Mygatt-Moore Quarry in the Brushy Basin Member of the Upper Jurassic Morrison Formation is one of the more important large dinosaur quarries in the formation, yielding fossils of sauropod dinosaurs including Apatosaurus, Camarasaurus, and an indeterminate diplodocine (cf. Diplodocus or Barosaurus), the theropod dinosaurs Allosaurus and Ceratosaurus, and the ornithischians Othnielosaurus and Mymoorapelta. Fossil wood and carbonized plants are known from the deposit, and carbonized dinosaur skin has also been discovered. We report here on a new U/Pb radiometric age for the Mygatt-Moore Quarry, from a smectitic mudstone collected at the quarry horizon. We isolated zircons using an ultrasonic separation technique and standard heavy liquid and magnetic methods, analyzed single zircons using a chemical abrasion method (CA-TIMS). The age determined for this dinosaur quarry, 152.18 ±0.29 Ma, places the quarry at the boundary between the Kimmeridgian and Tithonian stages of the Late Jurassic Period. This age can now be used to place the quarry into stratigraphic position with respect to other dated horizons in the Morrison Formation and other rock units worldwide. We will also use this age along with other ages to create a radiometrically based stratigraphic framework for the Morrison Formation.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 107--114
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Osteology of a large allosauroid theropod from the Upper Jurassic (Tithonian) Morrison Formation of Colorado, USA
    Autorzy:
    Dalman, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077330.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    dinosaur
    theropoda
    allosauridae
    Morrison Formation
    Upper Jurassic
    Colorado
    dinozaury
    teropody
    allozaury
    Formacja Morrisona
    górna jura
    Opis:
    Two partial skeletons of allosaurid theropods belonging to an adult and a juvenile from the Upper Jurassic (Tithonian) Morrison Formation of McElmo Canyon in Montezuma County, southwestern Colorado, were discovered in 1953 by the late Joseph T. Gregory and David Techter. The adult specimen consists of several isolated cranial and postcranial skeletal elements that are exceptionally well-preserved and include the left premaxilla, maxilla, dentary, teeth, quadratojugal, two caudal vertebrae, pubic peduncle, ischium, proximal tibia, a nearly complete left foot, and several isolated teeth, whereas the juvenile specimen is represented by the distal portion of the right dentary and a fragmentary splenial. The specimens represent a new species of Allosaurus, here named Allosaurus lucasi, which differs from Allosaurus fragilis by having a relatively short premaxilla and robust quadratojugal with short jugal process and a short quadrate process of the quadratojugal that is at the same level as the rostral quadratojugal ramus. The presence of a new species of Allosaurus in the Tithonian of North America provides further evidence of the taxonomic and morphological diversity of the Allosauridae clade and their continuous evolutionary success, which extended to the Cretaceous.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 159--180
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new diplodocoid sauropod dinosaur from the Upper Jurassic Morrison Formation of Montana, USA
    Autorzy:
    Harris, J D
    Dodson, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/22659.pdf
    Data publikacji:
    2004
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    phylogenesis
    Dicraeosauridae
    Diplodocoidea
    Upper Jurassic
    dinosaur
    Montana
    Jurassic
    paleobiogeography
    Diplodocidae
    USA
    sauropod dinosaur
    Dinosauria
    Morrison Formation
    paleontology
    Opis:
    A partial skeleton of a new sauropod dinosaur from the Upper Jurassic Morrison Formation (?Tithonian) of Montana is described. Suuwassea emilieae gen. et sp. nov. is diagnosed by numerous cranial, axial, and appendicular autapomorphies. The holotype consists of a premaxilla, partial maxilla, quadrate, braincase with partial skull roof, several partial and complete cranial and middle cervical, cranial dorsal, and caudal vertebrae, ribs, complete scapulocoracoid, humerus, partial tibia, complete fibula, calcaneus, and partial pes. It displays numerous synapomorphies of the Diplodocoidea, including characters of both the Diplodocidae (Apatosaurus + (Diplodocus + Barosaurus)) and Dicraeosauridae (Dicraeosaurus + Amargasaurus). Preliminary phylogenetic analysis indicates that Suuwassea is a diplodocoid more derived than rebbachisaurids but in a trichotomy with both the Diplodocidae and Dicraeosauridae. Suuwassea represents the first well−supported, North American, non−diplodocid representative of the Diplodocoidea and provides new insight into the origins of both the Diplodocidae and Dicraeosauridae.
    Źródło:
    Acta Palaeontologica Polonica; 2004, 49, 2
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Redescription of the type specimens for the Late Jurassic rhynchocephalian Opisthias rarus and a new specimen of Theretairus antiquus from Quarry 9, Morrison Formation, Wyoming, USA
    Autorzy:
    Herrera-Flores, J.A.
    Stubbs, T.L.
    Sour-Tovar, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/31341410.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    paleontology
    Jurassic
    Late Jurassic
    rhynchocephalian
    Rhynchocephalia
    Opisthias rarus
    new species
    Theretairus antiquus
    Lepidosauria
    Morrison Formation
    Wyoming
    USA
    Źródło:
    Acta Palaeontologica Polonica; 2022, 67, 3; 623-630
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Pathological phalanges in a camarasaurid sauropod dinosaur and implications on behaviour
    Autorzy:
    Tschopp, E.
    Wings, O.
    Frauenfelder, T.
    Rothschild, B.M.
    Powiązania:
    https://bibliotekanauki.pl/articles/20890.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    pathology
    paleopathology
    camarasaurid
    sauropod dinosaur
    dinosaur
    animal behaviour
    Dinosauria
    Sauropoda
    osteoarthritis
    osteochondrosis
    bone tumour
    Morrison Formation
    Jurassic
    Opis:
    Several types of pathological bony overgrowth are known from various dinosaur taxa but, except for stress fractures, are rarely reported from appendicular elements. Herein we describe pathological manual and pedal phalanges of a camarasaurid sauropod (SMA 0002), which show features rarely recognised in non-avian dinosaurs. They include lateral osteophytes and smoothing of phalangeal articular surfaces, a deep pit, proximal enthesophytes in pedal unguals, distal overgrowth associated with a fracture, and a knob-like overgrowth lateral to the distal condyles of a pedal phalanx. Their causes were assessed by means of visual examination, CT scans, and bone histology, where possible. The lateral osteophytes are interpreted as symptoms of osteoarthritis. The ossified tendon insertions in the unguals are most probably the result of prolonged, heavy use of the pedal claws, possibly for scratch-digging. The distal overgrowth is interpreted to have developed due to changed stress regimes, and to be the cause for the fracture. The deep pit represents most likely a case of osteochondrosis, whereas the knob-like overgrowth likely represents a post-traumatic phenomenon not previously reported in dinosaurs. The study confirms that a rigorous assessment of pathologies can yield information about behaviour in long-extinct animals.
    Źródło:
    Acta Palaeontologica Polonica; 2016, 61, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New data on small theropod dinosaurs from the Upper Jurassic Morrison Formation of Como Bluff, Wyoming, USA
    Autorzy:
    Dalman, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077332.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    dinosaurs
    theropoda
    Upper Jurassic
    Morrison Formation
    Como Bluff
    western USA
    dinozaury
    teropody
    górna jura
    Formacja Morrisona
    zachodnie USA
    Opis:
    In 1879, Othniel C. Marsh and Arthur Lakes collected in the Upper Jurassic Morrison Formation Quarry 12 at Como Bluff, Wyoming, USA, several isolated axial and appendicular skeletal elements of small theropod dinosaurs. Since the discovery the specimens remained unnoticed for over a century. The skeletal remains of small theropods are rare at Como Bluff and throughout the Morrison Formation. Their bones are delicately constructed, so they are not as well-preserved as the bones of large-bodied theropods. The bones of small theropods described here were found mixed with isolated crocodile teeth and turtle shells. Comparison of the skeletal materials with other known theropods from the Morrison Formation reveals that some of the bones belong to a very small juvenile Allosaurus fragilis and Torvosaurus tanneri and also to a new ceratosaur taxon, here named Fosterovenator churei, whereas the other bones represent previously unidentified juvenile taxa of basal tetanuran and coelurid theropods. The discovery and description of these fossil materials is significant because they provide important information about the Upper Jurassic terrestrial fauna of Quarry 12, Como Bluff, Wyoming. The presence of previously unidentified theropod taxa in the Morrison Formation indicates that the diversity of basal tetanuran and coelurid theropods may have been much greater than previously expected. Although the fossil material here described is largely fragmentary, it is tenable that theropods of different clades co-existed in the same ecosystems at the same time and most likely competed for the same food sources.
    Źródło:
    Volumina Jurassica; 2014, 12, 2; 181--196
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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