Beipiaosaurus

Beipiaosaurus

The exact classification of therizinosaurs had in the past been hotly debated, since their prosauropod-like teeth and body structure indicate that they were generally herbivorous, unlike typical theropods. Beipiaosaurus, being considered to be a primitive therizinosauroid, has features which suggest that all therizinosauroids, including the more derived Therizinosauridae, to be a maniraptoran coelurosaurian theropods, not sauropodomorph or ornithischian relatives as once believed.

The type specimen of Beipiaosaurus inexpectus, holotype IVPP V11559, was recovered in the Jianshangou Beds of the Yixian Formation in Liaoning Province, China. The specimen was collected in sediment deposited during the Aptian stage of the Cretaceous period, approximately 125 to 124 million years ago.^[2] This specimen is housed in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology, in Beijing, China. It consists of a partial, sub-adult, skeleton that is largely disarticulated. A significant number of fossilized bones were recovered, including: cranial fragments, a mandible, teeth, three cervical vertebrae, four dorsal vertebrae, four dorsal ribs, two sacral vertebrae, twenty-five caudal vertebrae, a pygostyle, three chevrons, an incomplete furcula and scapula, two coracoids, a complete forelimb, a partial forelimb, both ilia, an incomplete pubis, and incomplete ischium, a femur, both tibiae (one incomplete), an incomplete fibula, an astragalus, a calcaneum, several tarsals, metatarsals, and unguals, and remains of the integument, including feathers.

Skin impressions from the type specimen of B. inexpectus indicated that the body was covered predominately by downy feather-like fibers, similar to those of Sinosauropteryx, but longer, and are oriented perpendicular to the arm. Xu et al., who described the specimen, suggested that these downy feathers represent an intermediate stage between Sinosauropteryx and more advanced birds (Avialae).^[1] The tail was covered in feathers between four and seven centimeters long, consisting of parallel filaments with a width of 1.5 millimeters, without a trace of pennaceous feathers or a tail fan.

Spinosaurus

       

                              Spinosaurus

Spinosaurus was among the largest of all known carnivorous dinosaurs, possibly larger than Tyrannosaurus and Giganotosaurus. Estimates published in 2005, 2007, and 2008 suggested that it was between 12.6–18 metres (41–59 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. A new estimate published in 2014 and based on a more complete specimen, supported the earlier research, finding that Spinosaurus could reach lengths greater than 15 m (49 ft). The skull of Spinosaurus was long and narrow, similar to that of a modern crocodilian. Spinosaurus is known to have eaten fish, and most scientists believe that it hunted both terrestrial and aquatic prey; evidence suggests that it lived both on land and in water as a modern crocodilian does. The distinctive spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display.

 Spinosaurus appeared in the 2001 film Jurassic Park III, replacing Tyrannosaurus as the main antagonist. The film's consulting paleontologist John R. Horner was quoted as saying: "If we base the ferocious factor on the length of the animal, there was nothing that ever lived on this planet that could match this creature [Spinosaurus]. Also my hypothesis is that T-rex was actually a scavenger rather than a killer.

Spinosaurus was really the predatory animal." (He has since retracted the statement about T. Rex being a scavenger.) In the film, Spinosaurus was portrayed as larger and more powerful than Tyrannosaurus: in a scene depicting a battle between the two resurrected predators, Spinosaurus emerges victorious by snapping the tyrannosaur's neck. In the fourth film Jurassic World, there is a nod to this fight where the T-Rex smashes through the skeleton of a Spinosaurus in the climatic fight near the end of the film.

Uroplatus

Uroplatus

Uroplatus is a genus of geckos, commonly referred to as leaf-tail geckos, leaf-tailed geckos, or flat-tailed geckos, which are endemic to Madagascar and its coastal islands, such as Nosy Be. They are nocturnal, insectivorous lizards found exclusively in primary and secondary forest.



All Uroplatus species have highly cryptic colouration, which acts as camouflage, most being grayish-brown to black or greenish-brown with various markings resembling tree bark. There are two variations of this camouflage: leaf form, and bark form. The leaf form is present in only four described species, U. phantasticus, U. ebenaui, U. finiavana, and U. malama, which are also the smallest species. All other forms blend in well with tree bark upon which they rest during the day. Some of these tree bark forms have developed a flap of skin, running the length of the body, known as a "dermal flap", which they lay against the tree during the day, scattering shadows, and making their outline practically invisible. These geckos bear a resemblance to geckos of the genera Phyllurus and Saltuarius of Australia. This is an example of convergent evolution.
The skull of Uroplatus is strongly ossified, with an extremely high tooth count and incipient secondary palate.

Habitat destruction and deforestation in Madagascar is the primary threat to the future of Uroplatus geckos as well as collection for the pet trade.^[6] The World Wide Fund for Nature (WWF) lists all of the Uroplatus species on their "Top ten most wanted species list" of animals threatened by illegal wildlife trade, because of it "being captured and sold at alarming rates for the international pet rade".It is a CITES Appendix 2 protected animal

Baryonyx

Baryonyx (/ˌbæriˈɒnᵻks/) is a genus of theropod dinosaur which lived in the Barremian stage of the early Cretaceous Period, about 130–125 million years ago. The holotype specimen was discovered in 1983 in Surrey, England, and the animal was named Baryonyx walkeri in 1986. The genus name, Baryonyx, means "heavy claw" and alludes to the animal's very large claw on the first finger; the specific name (walkeri) refers to its discoverer, amateur fossil hunter William J. Walker. Fragmentary specimens were later discovered in other parts of the United Kingdom and Iberia. The holotype specimen is one of the most complete theropod skeletons from the UK, and its discovery attracted media attention.

The skull of Baryonyx is incompletely known, and much of the middle and hind portions are not preserved. The full length of the skull has been estimated to be 950 mm (37.4 in), based on comparison with that of the related genus Suchomimus (which is 20% larger). It was elongated, and the front 170 mm (6.6 in) of the premaxillae formed a long, low snout (rostrum) with a rounded upper surface. The nostrils, far back from the tip, passed horizontally from one side of the skull to the other. The front 130 mm (5.1 in) of the snout expanded into a spatulate (flared outwards to the sides), "terminal rosette" shape similar to the modern gharial, and the front 70 mm (2.7 in) of the lower margin was downturned. The snout was very narrow just behind the rosette. The creature's maxilla and premaxilla fit together in a complex articulation, resulting in a strongly curved tooth row. The gap in the row is comparable to that of Dilophosaurus. The front 140 mm (5.5 in) of the dentary in the mandible curved upwards towards this area, and the gap between the upper and lower jaw is known as the subrostral notch. The snout had extensive pits (which would have been exits for blood vessels and nerves), and the maxilla appears to have housed sinuses.^[2][6]

Most of the teeth found with the holotype specimen were not attached to the skull; a few remained in the upper jaw, and only small replacement teeth were in the lower jaw. The teeth had the shape of recurved cones, flattened somewhat sideways. The larger teeth were less recurved than the smaller ones, but were otherwise uniform. The roots were very long, and the teeth slender. The carinae (edges) of the teeth were finely serrated with denticles on the front and back. There were seven narrow, uniform denticles per millimetre (0.039 in), more than in most theropods. Some of the teeth were fluted, with six to eight ridges along the length of their inner sides and fine-grained enamel.

T-Rex

T-Rex

                                                            

The T-rex is from the Cretaceous period 68 to 66 million years ago. It was the last known member of the tyrannosaurids, and among the last non-avian dinosaurs to exist before the Cretaceous- Paleogene extinction event.

The Tyrannosaurus has a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, Tyrannosaurus fore limbs were short but unusually powerful for their size and had two clawed digits.

More than 50 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. 

Tyrannosaurus rex was one of the largest land carnivores of all time; the largest complete specimen, located at the Field Museum of Natural History.

The generic name is derived from the Greek words tupavvoc (tyrannos, meaning" tyrant") and Oavpoc (sauros, meaning "lizard").

The T-rex was one of the largest land predators during its time, which grew at an average length of 43 feet or 13 meters. Although some dinosaurs exceeded or even competed with its size, it was still considered the biggest carnivore in that period. At the hips, it measured approximately 13 feet or 4 meters high. The average T-rex weighed more or less 7.5 short tons or 6.8 metric tons. It was an apex predator, which preyed on ceratopsians and hadrosaurs. However, some paleontologists believe that the T-rex was more of a scavenger rather than an apex predator.