Temat: Theropoda - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Dinosaur footprints from the Upper Jurassic of Błaziny, Poland
Autorzy:: Gierliński, G.
Niedźwiedzki, G.
Tematy:: Polska
Late Jurassic
theropoda
Sauropoda
tracks; Pokaż więcej
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/2059882.pdf Link otwiera się w nowym oknie
Opis:: New dinosaur tracks are reported from the Late Jurassic platform carbonates of Poland. Footprints discovered in a new tracksite of Błaziny resemble large theropod ichnite of Megalosauripus sensu Lockley et al., 1998 and sauropod tracks of Brontopodus Farlow et al., 1989.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Isolated theropod teeth from the Cretaceous strata of Khouribga, Morocco
Autorzy:: Niedźwiedzki, G.
Gierliński, G.
Tematy:: Morocco
Cretaceous
theropoda
dinosauria
Carcharodontosauridae
Spinosauridae; Pokaż więcej
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/2059918.pdf Link otwiera się w nowym oknie
Opis:: Predatory dinosaur (Theropoda) teeth are described from Khouribga near Casablanca (Ad-Dar al-Bajda) in northern Morocco. A morphological study of specimens shows that two teeth represent the family Spinosauridae. A third tooth shows features characteristic of the genus Carcharodontosaurus. These are the first finds of dinosaurs from Khouribga.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Osteology of the unenlagiid theropod Neuquenraptor argentinus from the Late Cretaceous of Patagonia
Autorzy:: BRISSÓN EGLI, FEDERICO
ARANCIAGA ROLANDO, ALEXIS M.
AGNOLÍN, FEDERICO L.
NOVAS, FERNANDO E.
Tematy:: dinosauria
theropoda
unenlagiidae
neuquenraptor
cretaceous
argentina
patagonia; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/945635.pdf Link otwiera się w nowym oknie
Opis:: Neuquenraptor argentinus was described as the first undoubted deinonychosaurian theropod from Gondwana. The only known specimen is represented by a fragmentary skeleton, including a nearly complete foot, coming from Late Cretaceous beds of Neuquén Province, Patagonia, Argentina. Neuquenraptor was later considered as belonging to the Southern Hemisphere paravian clade Unenlagiidae, and proposed as a junior synonym of Unenlagia comahuensis. The aim of the present paper is to include a detailed anatomical description of Neuquenraptor (up to the date only known by a preliminary description). Comparisons with other paravians, especially unenlagiids, resulted in the finding of characters that may be considered as diagnostic of Unenlagiidae (e.g., scar-like fourth trochanter of femur, metatarsal II with tongue-shaped process over the caudal surface of metatarsal III, well-developed convex longitudinal plantar crest of metatarsal IV). Furthermore, comparisons between Neuquenraptor and Unenlagia are carried out with the aim to evaluate the possible synonymy between these taxa. These comparisons indicate that at least two similar-sized unenlagiids were present on the Portezuelo Formation. However, in concordance with previous authors, we are not able to support nor dismiss the possible synonymy between Unenlagia and Neuquenraptor. Additional findings of unenlagiid fossils from the Portezulo Formation will help to clarify the taxonomic status of these taxa.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Why tyrannosaurid forelimbs were so short: An integrative hypothesis
Autorzy:: Padian, Kevin
Tematy:: Dinosauria
Theropoda
Tyrannosaurus
Abelisaurus
Carcharodontosaurus
predation
limb proportions; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/2216272.pdf Link otwiera się w nowym oknie
Opis:: The unusually shortened limbs of giant theropods, including abelisaurids, carcharodontosaurids, and derived tyrannosauroids such as Tyrannosaurus rex have long been an object of wonder, speculation, and even derision on the part of both paleontologists and the public. Two questions commonly asked are “Why did the forelimbs become so short?” and “What did the animals use such short forelimbs for, if for anything?” Because basal tyrannosauroids and their outgroups, as well as the outgroups of other giant theropods, had longer forelimbs, the foreshortening of these elements in derived taxa was secondary, and it ostensibly involved a shift in developmental timing of the forelimb elements. Factors proposed to have influenced the evolutionary foreshortening include natural selection, sexual selection, energetic compensation, ontogenetic vagaries, and rudimentation due to disuse. Hypotheses of use have varied from a supporting anchor that allows the hindlimbs a purchase to stand from a reclining position to a pectoral version of pelvic claspers during intercourse to a sort of waving display during sexual or social selection. None of these hypotheses explain selective regimes for reduction; at best, they might argue for maintenance of the limb, but in all cases a larger limb would have suited the function better. It is likely that we have been looking the wrong way through the telescope, and that no specific function of the forelimbs was being selected; instead, another crucial adaptation of the animal profited from forelimb reduction. Here I propose, in the context of phylogenetic, ontogenetic, taphonomic, and social lines of evidence, that the forelimbs became shorter in the context of behavioral ecology: the great skull and jaws provided all the necessary predatory mechanisms, and during group-feeding on carcasses, limb reduction was selected to keep the forelimbs out of the way of the jaws of large conspecific predators, avoiding injury, loss of blood, amputation, infection, and death. A variety of lines of evidence can test this hypothesis.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Oviraptorosaur tail forms and functions
Autorzy:: Persons,IV, W.S.
Currie, P.J.
Norell, M.A.
Tematy:: Dinosauria
paleozoology
Theropoda
Oviraptorosauria
oviraptorosaur
pygostyle
caudal musculature
functional morphology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/945893.pdf Link otwiera się w nowym oknie
Opis:: Oviraptorosaur caudal osteology is unique among theropods and is characterized by posteriorly persistent and exceptionally wide transverse processes, anteroposteriorly short centra, and a high degree of flexibility across the pre-pygostyle vertebral series. Three-dimensional digital muscle reconstructions reveal that, while oviraptorosaur tails were reduced in length relative to the tails of other theropods, they were muscularly robust. Despite overall caudal length reduction, the relative size of the M. caudofemoralis in most oviraptorosaurs was comparable with those of other non-avian theropods. The discovery of a second Nomingia specimen with a pygostyle confirms that the fused terminal vertebrae of the type specimen were not an abnormality. New evidence shows that pygostyles were also present in the oviraptorosaurs Citipati and Conchoraptor. Based on the observed osteological morphology and inferred muscle morphology, along with the recognition that many members of the group probably sported broad tail-feather fans, it is postulated that oviraptorosaur tails were uniquely adapted to serve as dynamic intraspecific display structures. Similarities, including a reduced vertebral series and a terminal pygostyle, between the tails of oviraptorosaurs and the tails of theropods widely accepted as basal members of the Avialae, appear to be convergences.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: A new approach to evaluate the cursorial ability of the giant theropod Giganotosaurus carolinii
Autorzy:: Blanco, R E
Mazzetta, G V
Tematy:: Cretaceous
Theropoda
Dinosauria
theropod
dinosaur
Giganotosaurus
South America
Giganotosaurus carolinii; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/21508.pdf Link otwiera się w nowym oknie
Opis:: The cursorial capability of the South American giant theropod Giganotosaurus carolinii should have been quite limited taking into account the strength indicator of its femur (approximately 7 GPa⁻¹) as well as the risk of experiencing grave or even lethal injuries involved in the falling of this multitonne animal on a run. However, even at low speeds a fall would have caused serious injuries. Thus, in accordance to the approach developed in this study, the maximum speed of Giganotosaurus should be not that which will implicate corporal lesions with minimum probability of lethalness. Instead, its maximum speed should be that which would permit the recovery of body equilibrium as each step is taken. Taking into consideration this approach, an indicator of stability is defined for bipedal, cursorial animals. This indicator is determined by the relationship between the time available for the movement of hip joint during the retraction of a hindlimb and the time needed to move the opposite hindlimb by an angle (in function of the speed) of sufficient magnitude as to facilitate the recovery of body equilibrium. This indicator was used to estimate the maximum speed of locomotion of Giganotosaurus (about 14 m s⁻¹) at which, from a kinematic point of view, the danger of falling does not exist.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: An enigmatic theropod Cryolophosaurus: reviews and comments on its paleobiology
Autorzy:: Yun, Changyu
Tematy:: Cryolophosaurus
dinosauria
theropoda
ecology
Antarctica
kriolofozaur
dinozaury
teropod
ekologia
Antarktyda; Pokaż więcej
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/2060953.pdf Link otwiera się w nowym oknie
Opis:: Cryolophosaurus is a genus of theropod dinosaur that is characterized by its distinctive crest formed by dorsally expanded lacrimals. Although its fossils are rare, currently recognized materials suggest this taxon was the largest predator in the Early Jurassic times in Antarctica, indicating it was the apex predator in its ecosystem. The skeleton of Cryolophosaurus bears both advanced and basal characteristics of theropods, making its position within theropod phylogenetic tree controversial. Its unusual anatomical features, size, and the habitat located close to the Jurassic polar circle all differ from other Early Jurassic theropods, indicating it was one of the most ecologically significant taxon of all theropods.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Scapular orientation in theropods and basal birds, and the origin of flapping flight
Autorzy:: Senter, P
Tematy:: bird
Archaeopteryx
Aves
flight
Theropoda
flapping flight
theropod
basal bird
paleontology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/21712.pdf Link otwiera się w nowym oknie
Opis:: Basal birds such as Archaeopteryx and Confuciusornis are typically portrayed as flapping fliers. However, here I show that shoulder joint orientation in these animals prevented elevation of the humerus above the dorsum, thereby preventing use of the recovery stroke, an important part of flapping flight. In members of the clade Ornithothoraces, which includes extant birds and the extinct avian clade Enantiornithes, the shoulder joint is reoriented to permit elevation of the humerus above the dorsum, permitting flapping flight. Although basal birds may have glided, flapping flight began significantly later in avian evolution than has been thought.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Macroevolutionary and morphofunctional patterns in theropod skulls: A morphometric approach
Autorzy:: Foth, C.
Rauhut, O.W.M.
Tematy:: macroevolution
theropod dinosaur
skull
Theropoda
feeding ecology
biomechanics
evolution
Mesozoic
paleontology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/21033.pdf Link otwiera się w nowym oknie
Opis:: Theropod dinosaurs are one of the most remarkable lineages of terrestrial vertebrates in the Mesozoic, showing high taxo− nomic and ecological diversity. We investigate the cranial diversity of non−avian theropods and some basal birds, using geometric morphometrics to obtain insights into the evolutionary modifications of the skull. Theropod skulls mostly vary in the shape of the snout and length of the postorbital region (principal component [PC] 1), with further variation in orbit shape, depth of the postorbital region, and position of the jaw joint (PC 2 and PC 3). These results indicate that the cranial shape of theropods is closely correlated with phylogeny and dietary preference. Skull shapes of non−carnivorous taxa dif− fer significantly from carnivorous taxa, suggesting that dietary preference affects skull shape. Furthermore, we found a significant correlation between the first three PC axes and functional proxies (average maximum stress and an indicator of skull strength). Interestingly, basal birds occupy a large area within the morphospace, indicating a high cranial, and thus also ecological, diversity. However, we could include only a small number of basal avialan species, because their skulls are fragile and there are few good skull reconstructions. Taking the known diversity of basal birds from the Jehol biota into account, the present result might even underestimate the morphological diversity of basal avialans.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Caudipteryx as a non-avalian theropod rather than a flightless bird
Autorzy:: Dyke, G J
Norell, M.A.
Tematy:: bird
Avialae
feather
Cretaceous
Caudipteryx zoui
China
Theropoda
Dinosauria
Yixian Formation
paleontology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/22434.pdf Link otwiera się w nowym oknie
Opis:: Caudipteryx zoui is a small enigmatic theropod known from the Early Cretaceous Yixian Formation of the People’s Republic of China. From the time of its initial description, this taxon has stimulated a great deal of ongoing debate regarding the phylogenetic relationship between non−avialan theropods and birds (Avialae) because it preserves structures that have been uncontroversially accepted as feathers (albeit aerodynamically unsuitable for flight). However, it has also been proposed that both the relative proportions of the hind limb bones (when compared with overall leg length), and the position of the center of mass in Caudipteryx are more similar to those seen in extant cusorial birds than they are to other non−avialan theropod dinosaurs. This conclusion has been used to imply that Caudipteryx may not have been correctly interpreted as a feathered non−avialan theropod, but instead that this taxon represents some kind of flightless bird. We review the evidence for this claim at the level of both the included fossil specimen data, and in terms of the validity of the results presented. There is no reason—phylogenetic, morphometric or otherwise—to conclude that Caudipteryx is anything other than a small non−avialan theropod dinosaur.
Dostawca treści:: Biblioteka Nauki

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