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Titanosauridae
Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch ''et al.'' in 2004 as the most recent common ancestor of ''Malawisaurus'' and ''Saltasaurus'' and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek , meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch ''et al.'' include caudal vertebrae with strongly concave front faces (procoely), although the farthest vertebrae are not procoelous. History of research In 1895, Richard Lydekker named the family Titanosauridae to summarize sauropods with procoelous (concave on the front) caudal vertebrae. The name Titanosauridae has since been widely used, and was defined by Salgado and colleagues (1997), Gonzalaz-Riga (2003), and Salgado (2003) as a node-based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanosaur
Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as ''Patagotitan''—estimated at long with a weight of —and the comparably-sized ''Argentinosaurus'' and ''Puertasaurus'' from the same region. The group's name alludes to the mythological Titans of ancient Greek mythology, via the type genus (now considered a '' nomen dubium)'' ''Titanosaurus''. Together with the brachiosaurids and relatives, titanosaurs make up the larger sauropod clade Titanosauriformes. Titanosaurs have long been a poorly-known group, and the relationships between titanosaur species are still not well-understood. Description Titanosauria have the largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanosauridae
Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch ''et al.'' in 2004 as the most recent common ancestor of ''Malawisaurus'' and ''Saltasaurus'' and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek , meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch ''et al.'' include caudal vertebrae with strongly concave front faces (procoely), although the farthest vertebrae are not procoelous. History of research In 1895, Richard Lydekker named the family Titanosauridae to summarize sauropods with procoelous (concave on the front) caudal vertebrae. The name Titanosauridae has since been widely used, and was defined by Salgado and colleagues (1997), Gonzalaz-Riga (2003), and Salgado (2003) as a node-based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saltasaurus
''Saltasaurus'' (which means "lizard from Salta") is a genus of saltasaurid dinosaur of the Late Cretaceous period of Argentina. Small among sauropods, though still heavy by the standards of modern creatures, ''Saltasaurus'' was characterized by a short neck and stubby limbs. It was the first genus of sauropod known to possess armour of bony plates embedded in its skin. Such small bony plates, called osteoderms, have since been found on other titanosaurians. Discovery The fossils of ''Saltasaurus'' were excavated by José Bonaparte, Martín Vince and Juan C. Leal between 1975 and 1977 at the Estancia "El Brete". The find was in 1977 reported in the scientific literature. ''Saltasaurus'' was named and described by Bonaparte and Jaime E. Powell in 1980. The type species is ''Saltasaurus loricatus''. Its generic name is derived from Salta Province, the region of north-west Argentina where the first fossils were recovered. The specific name means "protected by small armoured plat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutitanosauria
Eutitanosauria is a clade of titanosaurs, encompassing the more derived members of the group and characterized by the absence of the hyposphene-hypantrum articulation and possibly the presence of osteoderms. The group was first named by Sanz and colleagues in 1999, who used it to unite the group of '' Argyrosaurus'', ''Lirainosaurus'', ''Saltasaurus'' and the Peiropolis titanosaur. However, this definition was not used as it made the group equivalent to Saltasauridae, so Saldago redefined it in 2003 to be all titanosaurs closer to ''Saltasaurus'' than ''Epachthosaurus''. This definition created Eutitanosauria as the sister group to Epachthosaurinae (''Epachthosaurus'' but not ''Saltasaurus''), but was problematic due to the variable nature of ''Epachthosaurus''. Eutitanosauria was often broadly similar to Lithostrotia, and has often been unused or unlabelled on phylogenies. Sometimes ''Epachthosaurus'' would be more primitive than ''Malawisaurus'', making Eutitanosauria more encom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derived Trait
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropod Caudal Pneumaticity
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] |
Titanosaurus
''Titanosaurus'' (; ) is a dubious genus of sauropod dinosaurs, first described by Richard Lydekker in 1877.R. Lydekker. (1877). Notices of new and other Vertebrata from Indian Tertiary and Secondary rocks. ''Records of the Geological Survey of India'' 10(1):30-43 It is known from the Maastrichtian (Upper Cretaceous) Lameta Formation of India. Discovery and naming ''Titanosaurus'', literally meaning 'titanic lizard', was named after the mythological Titans. ''Titanosaurus'' was the first Indian dinosaur to be named and properly described, having been recorded for the first time in 1877. The type species, ''T. indicus'', was named in 1877, and the second species, ''T. blanfordi'', was named in 1879.R. Lydekker. (1879). Fossil Reptilia and Batrachia. ''Memoirs of the Geological Survey of India. Palaeontologia Indica, Series IV. Indian Pretertiary Vertebrata'' 1(3):1-36 Both species were named by Richard Lydekker. ''T. indicus'' and ''T. blanfordi'' are 70 million years old. ''Ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Node-based Taxon
Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is currently regulated by the '' International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature ties names to clades, groups consisting of an ancestor and all its descendants. These groups can equivalently be called monophyletic. There are slightly different ways of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the named taxon. Listing all these organisms (i.e. providing a full circumscription) requires the full phylogenetic tree to be known. In practice, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Vertebrae
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoderms
Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amphibians), various groups of dinosaurs (most notably ankylosaurs and stegosaurians), phytosaurs, aetosaurs, placodonts, and hupehsuchians (marine reptiles with possible ichthyosaur affinities). Osteoderms are uncommon in mammals, although they have occurred in many xenarthrans ( armadillos and the extinct glyptodonts and mylodontid and scelidotheriid ground sloths). The heavy, bony osteoderms have evolved independently in many different lineages. The armadillo osteoderm is believed to develop in subcutaneous dermal tissues. These varied structures should be thought of as anatomical analogues, not homologues, and do not necessarily indicate monophyly. The structures are however derived from scutes, common to all classes of amnio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
