Showing posts with label dinosaur. Show all posts
Showing posts with label dinosaur. Show all posts

Tuesday, October 10, 2023

Compsognathidae

 Compsognathidae is a family of coelurosaurian theropod dinosaurs. Compsognathids were small carnivores, generally conservative in form, hailing from the Jurassic and Cretaceous Periods.


 

Monday, March 20, 2023

K–Pg boundary

 The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K–T) boundary, is a geological signature, usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end of the Cretaceous Period, the last period of the Mesozoic Era, and marks the beginning of the Paleogene Period, the first period of the Cenozoic Era. Its age is usually estimated at around 66 million years, with radiometric dating yielding a more precise age of 66.043 ± 0.011 Ma.

 


Sunday, September 27, 2015

Allosauroidea

Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Metriacanthosauridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae. The oldest-known allosauroid, Shidaisaurus jinae, appeared in the early Middle Jurassic (probably Bajocian stage) of China. The last known definitive surviving members of the group died out around 93 million years ago in Asia (Shaochilong) and South America (Mapusaurus), though the megaraptorans, including the late-surviving Orkoraptor of the Late Cretaceous, (Maastrichtian stage), may belong to the group as well. Additional, but highly fragmentary, remains probably belonging to carcharodontosaurids have been found from the Campanian-Maastrichtian boundary (70 Ma ago) in Brazil. Allosauroids had long, narrow skulls, large orbits, three-fingered hands, and usually had "horns" or ornamental crests on their heads. The most famous and best understood allosauroid is the North American genus Allosaurus.

Sunday, November 3, 2013

Jurassic


The Jurassic is a geologic period and system that extends from about 199.6± 0.6 Mya (million years ago) to 145.5± 4 Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period is marked by the major Triassic–Jurassic extinction event. However, the end of the Jurassic Period did not witness any major extinction event. The start and end of the period are defined by carefully selected locations; the uncertainty in dating arises from trying to date these horizons.

The chronostratigraphic term "Jurassic" is directly linked to the Jura Mountains. Alexander von Humboldt recognized the mainly limestone dominated mountain range of the Jura Mountains as a separate formation that was not at the time included in the established stratigraphic system defined by Abraham Gottlob Werner and named it “Jurakalk” in 1795. The name “Jura” is derived from the celtic root “jor” which was Latinised into “juria”, meaning forest (i.e. “Jura” is forest mountains).

Thursday, July 12, 2012

Zhuchengtyrannus

Zhuchengtyrannus (meaning "Zhucheng tyrant") is a genus of carnivorous theropod dinosaur from the Late Cretaceous period. It is a tyrannosaurine tyrannosaurid which lived during the late Cretaceous period in what is now Zhucheng, Shandong Province of China. It is known from a maxilla and associated dentary (lower jaw with teeth) recovered from the Wangshi Group, dating to about 70 million years ago. It was one of the largest known carnivorous theropods, measuring about 11 m (36 ft) in length, 4 metres (13 ft) tall, and 6 tons in weight. The dentary is only a little smaller than the largest Tyrannosaurus rex jawbone found.

The place where the dinosaur has been found was a flood plain in the Cretaceous period and contains one of the highest concentrations of dinosaur bones in the world.

Tuesday, January 31, 2012

Albertosaurus


Albertosaurus (meaning "Alberta lizard") is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, more than 70 million years ago. The type species, A. sarcophagus, was restricted in range to the modern-day Canadian province of Alberta, after which the genus is named. Scientists disagree on the content of the genus, with some recognizing Gorgosaurus libratus as a second species.

As a tyrannosaurid, Albertosaurus was a bipedal predator with tiny, two-fingered hands and a massive head with dozens of large, sharp teeth. It may have been at the top of the food chain in its local ecosystem. Although relatively large for a theropod, Albertosaurus was much smaller than its more famous relative Tyrannosaurus, probably weighing less than 2 metric tons.

Tuesday, June 14, 2011

Diplodocus


Diplodocus is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek διπλόος (diploos) "double" and δοκός (dokos) "beam", in reference to its double-beamed chevron bones located in the underside of the tail. These bones were initially believed to be unique to Diplodocus; however, they have since then been discovered in other members of the diplodocid family and in non-diplodocid sauropods such as Mamenchisaurus.

Tuesday, September 1, 2009

thagomizer


The thagomizer, or tail spikes, is an arrangement of four to ten spikes on the tails of particular dinosaurs of the clade Stegosauria, of which Stegosaurus stenops is the most familiar. The tail arrangement is believed to have been a defensive weapon against predators.

synanthrope

 A synanthrope (from ancient Greek σύν sýn "together, with" and ἄνθρωπος ánthrōpos "man") is an organism that evolve...