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Megaloolithid
Megaloolithidae is an oofamily of fossil egg of the Dinosauroid-spherulitic morphotype. They probably are the eggs of sauropods. Paleopathology Multilayered shell Megaloolithid eggs with multiple layers of eggshell have been preserved in the fossil record. Multilayered fossil eggs resemble those of modern forms in sometimes having incomplete extra layers and pore canals that don't properly align. The misalignment of the pore canals can prevent oxygen from getting to the embryo and cause it to suffocate. The term ''ovum in ovo'' has been used for multilayered dinosaur eggs although this is inaccurate use of the term. The greater abundance may indicate that these eggs were more prone to such pathologies, but are most likely due to a larger sample size of them. Megaloolithid eggs with a discretispherulitic morphotype In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaloolithus
''Megaloolithus'' is an oogenus of dinosaur egg. Some eggs belonging to this oogenus may have been laid by the titanosaur ''Hypselosaurus''. They are known for having thick eggshells, at least thick, and the nearly spherical shape of the eggs. They are primarily found in India and Europe, but some specimens have been found in South America. Species * ''M. aureliensis'' * ''M. baghensis'' * ''M. cylindricus'' * ''M. dhoridungriensis'' * ''M. jabalpurensis'' * ''M. khempurensis'' * ''M. mamillare'' * ''M. megadermus'' * ''M. microtuberculata'' * ''M. mohabeyi'' * ''M. petralta'' * ''M. problematica'' * ''M. siruguei'' * ''M. trempii'' * ''M. patagonicus'' Distribution Fossils of ''Megaloolithus'' have been found in:''Megaloolithus'' at |
Pseudomegaloolithus
''Pseudomegaloolithus'' is an oogenus of fossil Megaloolithidae, Megaloolithid egg from Morocco. It is known from eggshell fragments which are distinguished from other Megaloolithid eggs because of its thin shells, fan-shaped eggshell units, and the structure of the nodes and ridges on the eggshell surface. Some egg fragments from India, France, and Peru (some of which had previously been classified as ''Megaloolithus, Megaloolithus pseudomamillare'') may actually represent specimens of ''Pseudomegaloolithus''.M. Vianey-Liaud and N. López-Martínez. 1997. Late Cretaceous dinosaur eggshells from the Tremp basin, southern Pyrenees, Lleida, Spain. Journal of Paleontology 71(6):1157-1171 References Dinosaur reproduction Egg fossils Maastrichtian life Cretaceous Morocco Fossils of Morocco Fossil parataxa described in 1997 {{eggshell-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oofamily
Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains of the once- developing embryo inside, in which case it also contains body fossils. A wide variety of different animal groups laid eggs that are now preserved in the fossil record beginning in the Paleozoic. Examples include invertebrates like ammonoids as well as vertebrates like fishes, possible amphibians, and reptiles. The latter group includes the many dinosaur eggs that have been recovered from Mesozoic strata. Since the organism responsible for laying any given egg fossil is frequently unknown, scientists classify eggs using a parallel system of taxonomy separate from but modeled after the Linnaean system. This "parataxonomy" is called ''veterovata''. History The first named oospecies was '' Oolithes bathonicae'', a name given provisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosauroid-spherulitic
Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains of the once- developing embryo inside, in which case it also contains body fossils. A wide variety of different animal groups laid eggs that are now preserved in the fossil record beginning in the Paleozoic. Examples include invertebrates like ammonoids as well as vertebrates like fishes, possible amphibians, and reptiles. The latter group includes the many dinosaur eggs that have been recovered from Mesozoic strata. Since the organism responsible for laying any given egg fossil is frequently unknown, scientists classify eggs using a parallel system of taxonomy separate from but modeled after the Linnaean system. This " parataxonomy" is called ''veterovata''. History The first named oospecies was '' Oolithes bathonicae'', a name given pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropod
Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include ''Brachiosaurus'', ''Diplodocus'', ''Apatosaurus'' and ''Brontosaurus''. The oldest known unequivocal sauropod dinosaurs are known from the Early Jurassic. ''Isanosaurus'' and ''Antetonitrus'' were originally described as Triassic sauropods, but their age, and in the case of ''Antetonitrus'' also its sauropod status, were subsequently questioned. Sauropod-like sauropodomorph tracks from the Fleming Fjord Formation (Greenland) might, however, indicate the occurrence of the group in the Late Triassic. By the Late Jurassic (150 million yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Record
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphotype
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Vertebrate Paleontology
The ''Journal of Vertebrate Paleontology'' is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri Zidek (University of Oklahoma). It covers all aspects of vertebrate paleontology, including vertebrate origins, evolution, functional morphology, taxonomy, biostratigraphy, paleoecology, paleobiogeography, and paleoanthropology. The journal is published by Taylor & Francis on behalf of the Society of Vertebrate Paleontology. According to ''Journal Citation Reports'', the journal has a 2017 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 2.190. References External links * Paleontology journals Publications established in 1980 Quarterly journals English-language journals Taylor & Francis academic journals {{paleontology-jou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur Reproduction
Dinosaur reproduction was relevant to archosaur physiology, with newborns hatching from eggs. Dinosaurs did not nurture their offspring as mammals typically do, and because dinosaurs did not nurse, it is likely that most dinosaurs were capable of surviving on their own after hatching. Medullary bone A discovery of features in a ''Tyrannosaurus rex'' skeleton provided more evidence that dinosaurs and birds evolved from a common ancestor and, for the first time, allowed paleontologists to establish the sex of a dinosaur. When laying eggs, female birds grow a special type of bone between the hard outer bone and the marrow of their limbs. This '' medullary'' bone, which is rich in calcium, is used to make eggshells. The presence of endosteally derived bone tissues lining the interior marrow cavities of portions of the ''Tyrannosaurus rex'' specimen's hind limb suggested that ''T. rex'' used similar reproductive strategies, and revealed the specimen to be female. Further research has fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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