Shrews are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to different families or orders.
Ichthyostega is an extinct genus of limbed tetrapodomorphs from the Late Devonian of what is now Greenland. It was among the earliest four-limbed vertebrates ever in the fossil record and was one of the first with weight-bearing adaptations for terrestrial locomotion. Ichthyostega possessed lungs and limbs that helped it navigate through shallow water in swamps. Although Ichthyostega is often labelled a 'tetrapod' because of its limbs and fingers, it evolved long before true crown group tetrapods and could more accurately be referred to as a stegocephalian or stem tetrapod. Likewise, while undoubtedly of amphibian build and habit, it is not a true member of the group in the narrow sense, as the first modern amphibians appeared in the Triassic Period. Until finds of other early stegocephalians and closely related fishes in the late 20th century, Ichthyostega stood alone as a transitional fossil between fish and tetrapods, combining fish and tetrapod features. Newer research has shown that it had an unusual anatomy, functioning more akin to a seal than a salamander, as previously assumed.
Dimetrodon is an extinct genus of non-mammalian synapsid belonging to the family Sphenacodontidae that lived during the Cisuralian age of the Early Permian period, around 295–272 million years ago. With most species measuring 1.7–4.6 m (5.6–15.1 ft) long and weighing 28–250 kg (62–551 lb), the most prominent feature of Dimetrodon is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It was an obligate quadruped and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority of these coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have also been found in Germany and over a dozen species have been named since the genus was first erected in 1878.
Ambulocetus is a genus of early amphibious cetacean from the Kuldana Formation in Pakistan, roughly 48 or 47 million years ago during the Early Eocene (Lutetian). It contains one species, Ambulocetus natans, known solely from a near-complete skeleton. Ambulocetus is among the best-studied of Eocene cetaceans, and serves as an instrumental find in the study of cetacean evolution and their transition from land to sea, as it was the first cetacean discovered to preserve a suite of adaptations consistent with an amphibious lifestyle. Ambulocetus is classified in the group Archaeoceti—the ancient forerunners of modern cetaceans whose members span the transition from land to sea—and in the family Ambulocetidae, which includes Himalayacetus and Gandakasia.
Lystrosaurus is an extinct genus of herbivorous dicynodont therapsids from the late Permian and Early Triassic epochs. It lived in what is now Antarctica, India, China, Mongolia, European Russia and South Africa. Four to six species are currently recognized, although from the 1930s to 1970s the number of species was thought to be much higher. They ranged in size from that of a small dog to 8 feet (2.5 meters) long.
Venomous mammals are animals of the class Mammalia that produce venom, which they use to kill or disable prey, to defend themselves from predators or conspecifics or in agonistic encounters. Mammalian venoms form a heterogeneous group with different compositions and modes of action, from four orders of mammals: Eulipotyphla, Monotremata, Primates, and Chiroptera. To explain the rarity of venom delivery in Mammalia, Mark Dufton of the University of Strathclyde has suggested that modern mammalian predators do not need venom because they are able to kill quickly with their teeth or claws, whereas venom, no matter how sophisticated, requires time to disable prey.
Leptoceratops is a genus of ceratopsian dinosaur from the Late Cretaceous of North America. First found in Alberta in 1910, the type species Leptoceratops gracilis was named in 1914 by Barnum Brown for a partial skull and skeleton of two individuals found in the Scollard Formation of Alberta. Additional specimens found in the Scollard include one complete and two mostly complete skeletons together, uncovered in 1947 by Charles M. Sternberg. Specimens from Montana that were among the earliest referred to Leptoceratops have since been moved to their own genera Montanoceratops and Cerasinops, while new specimens of L. gracilis include bonebed remains from the Hell Creek Formation of Montana and a partial skeleton from the Lance Formation of Wyoming. Together with related taxa, Leptoceratops is the eponymous genus of the family Leptoceratopsidae. Leptoceratops is known from more than ten individuals, all from Maastrichtian deposits of Alberta, Montana and Wyoming, representing the entire skeleton.
Amargasaurus is a genus of sauropod dinosaur from the Early Cretaceous epoch of what is now Argentina. The only known skeleton was discovered in 1984 and is virtually complete, including a fragmentary skull, making Amargasaurus one of the best-known sauropods of its epoch. Amargasaurus was first described in 1991 and contains a single known species, Amargasaurus cazaui. It was a large animal, but small for a sauropod, reaching 9 to 13 meters in length. Most distinctively, it sported two parallel rows of tall spines down its neck and back, taller than in any other known sauropod. In life, these spines could have stuck out of the body as solitary structures that supported a keratinous sheath. An alternate hypothesis, now more favored, postulates that they could have formed a scaffold supporting a skin sail. They might have been used for display, combat, or defense.
Majungasaurus is a genus of abelisaurid theropod dinosaur that lived in Madagascar from 70 to 66 million years ago, at the end of the Cretaceous Period, making it one of the last-known non-avian dinosaurs that went extinct during the Cretaceous–Paleogene extinction event. The genus contains a single species, Majungasaurus crenatissimus. This dinosaur is also called Majungatholus, a name which is considered a junior synonym of Majungasaurus.
The hero shrew, also known as the armored shrew, is a large shrew native to the Congo Basin of Africa. Its features are typical of a white-toothed shrew − short legs, slender snout, dense fur − except for a highly unusual spinal column. It has corrugated interlocking vertebrae that are unique among mammals except for its sister species, Thor's hero shrew. This unique adaptation allows the animal to bear a huge amount of weight on its back − 72 kg (159 lb) according to an expedition team.
Scutisorex is a genus of African shrews, mammals of the family Soricidae. Members of the genus are the only known mammal species whose vertebrae interlock, a feature which, along with the general enlargement and strengthening of the backbone and ribs, allows them to bear remarkable loads. They also have well developed muscles for flexing their spine in the sagittal plane. It is thought that these adaptations allow the shrews to wedge open spaces between the trunks of palm trees and the stems of dead leaves, as well underneath logs and rocks, allowing them to partake of a reliable source of insect larvae and earthworms that would otherwise be inaccessible.
Amphicoelias is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during the Tithonian of what is now Colorado, United States. Amphicoelias was moderately sized at about 18 metres (59 ft) in length and 15 metric tons in body mass, shorter than its close relative Diplodocus. Its hindlimbs were very long and thin, and its forelimbs were proportionally longer than in relatives.
Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154 to 150 million years ago. It was first described by American paleontologist Elmer S. Riggs in 1903 from fossils found in the Colorado River valley in western Colorado, United States. Riggs named the dinosaur Brachiosaurus altithorax; the generic name is Greek for "arm lizard", in reference to its proportionately long arms, and the specific name means "deep chest". Brachiosaurus is estimated to have been between 18 and 22 meters long; body mass estimates of the subadult holotype specimen range from 28.3 to 46.9 metric tons. It had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. Atypically, Brachiosaurus had longer forelimbs than hindlimbs, which resulted in a steeply inclined trunk, and a proportionally shorter tail.
Aerosaurus is an extinct genus within Varanopidae, a family of non-mammalian synapsids. It lived between 252-299 million years ago during the Early Permian in North America. The name comes from Latin aes (aeris) “copper” and Greek sauros “lizard,” for El Cobre Canyon in northern New Mexico, where the type fossil was found and the site of former copper mines. Aerosaurus was a small to medium-bodied carnivorous synapsid characterized by its recurved teeth, triangular lateral temporal fenestra, and extended teeth row. Two species are recognized: A. greenleeorum (1937) and A. wellesi (1981).
Spinophorosaurus is a genus of sauropod dinosaur that lived in what is now Niger during the Middle Jurassic period. The first two specimens were excavated in the 2000s by German and Spanish teams under difficult conditions. The skeletons were brought to Europe and digitally replicated, making Spinophorosaurus the first sauropod to have its skeleton 3D printed, and were to be returned to Niger in the future. Together, the two specimens represented most of the skeleton of the genus, and one of the most completely known basal sauropods of its time and place. The first skeleton was made the holotype specimen of the new genus and species Spinophorosaurus nigerensis in 2009; the generic name refers to what was initially thought to be spiked osteoderms, and the specific name refers to where it was found. A juvenile sauropod from the same area was later assigned to the genus.
Gobiconodontidae is a family of extinct mammals that ranged from the mid-Jurassic to the early Late Cretaceous, though most common during the Early Cretaceous. The Gobiconodontids form a diverse lineage of carnivorous non-therian mammals, and include some of the best preserved Mesozoic mammal specimens.
The vertebral column, also known as the spinal column, spine or backbone, is the core part of the axial skeleton in vertebrate animals. The vertebral column is the defining and eponymous characteristic of the vertebrate endoskeleton, where the notochord found in all chordates has been replaced by a segmented series of mineralized irregular bones called vertebrae, separated by fibrocartilaginous intervertebral discs. The dorsal portion of the vertebral column houses the spinal canal, an elongated cavity formed by alignment of the vertebral neural arches that encloses and protects the spinal cord, with spinal nerves exiting via the intervertebral foramina to innervate each body segments.
William T. Stanley was an American mammalogist who was a manager of the collections at one of the world's largest natural history museums and a student of the mammals of eastern Africa. He was an evolutionary biologist and mammalogist, and at the time of his death was the director of the Field Museum of Natural History's Collections Center and the Collection Manager of the Field Museum's Collection of Mammals. Stanley studied the biogeography, ecology, evolution, and systematics of shrews, bats and rodents that live on mountains within Tanzania and surrounding countries.
Gordodon is an extinct genus of non-mammalian synapsid that lived during the Early Permian of what is now Otero County, New Mexico. It was a member of the herbivorous sail-backed family Edaphosauridae and contains only a single species, the type species G. kraineri. Gordodon is unusual among early synapsids for its teeth, which were arranged similarly to those of modern mammals and unlike the simple, uniform lizard-like teeth of other early herbivorous synapsids. Gordodon had large incisor-like teeth at the front, followed by a prominent gap between them and a short row of peg-like teeth at the back. Gordodon was also relatively long-necked for an early synapsid, with elongated and gracile vertebrae in its neck and back. Like other edaphosaurids, Gordodon had a tall sail on its back made from the bony neural spines of its vertebrae. The spines also had bony knobs on them, a common trait of edaphosaurids, but the knobs of Gordodon are also unique for being more slender, thorn-like and randomly arranged along the spines. It is estimated to have been rather small at 1 m in length excluding the tail and 34 kg (75 lb) in weight.
Danuvius guggenmosi is an extinct species of great ape that lived 11.6 million years ago during the Middle–Late Miocene in southern Germany. It is the sole member of the genus Danuvius. The area at this time was probably a woodland with a seasonal climate. A male specimen was estimated to have weighed about 31 kg (68 lb), and two females 17 and 19 kg. Both genus and species were described in November 2019.
