Triceratops horridus

Triceratops horridus (three horned face)

Kingdom- Animalia
Phylum- Chordata
Class- Reptilia
Order- Onithischia
Suborder-Ceratopsia
Family- Ceratopsidue
Genus- Triceratops

Diet: Herbivore

Height: 10 feet

Length: 30 feet

Weight: 4 to 6 tons

Time of Habitation: Late Cretaceous period 68-65 million years ago

Place of Habitation: Western north America

Triceratops were among the first dinosaurs to be found. The Triceratops was found in 1889 in Lance Creek, Wyoming. Some call Triceratops "The Last Dinosaur" because it is a rather common find in the youngest Cretaceous rock formations. Unlike other Ceratopsians the Triceratops frill was solid. Most Ceratopsians had large holes in the frill bone where jaw bones might have connected. The Triceratops however had a solid bone for it's frill. The jaw muscles still might have attached to the frill allowing more bite power for slicing up tough vegetation.

It was  highly debated whether or not Triceratops was capable of increased speed. It is now thought that the Triceratops could gallop like the modern day rhinoceroses. Triceratops got it's name from the three horns on it's head, two horns on it's frill above it's eyes and a horn on it's nose. These horns paired with the 6 foot wide frill made an excellent pair for numerous possible purposes. The frill might have been to protect the neck of the Triceratops from predators. Though the fossils of Triceratops do not indicate very long or sharp horns, it is thought that the horns were sheathed by a layer of keratin which is the same substance as human fingernails. These long sharp horns would have been perfect for charging predators and inflicting serious wounds.

There is slight speculation that the frill might have been for thermal regulation. Due to the presence of blood vessels in the frill, the most widely accepted theory is that the frill was used for display. These possible display uses range from attracting a mate, to territorial displays, to males challenging one another for the right to mate. The horns would then have been used between males when flashing frills didn't determine a dominant male. There are specimens of Triceratops from all ages, hatchling to adult. Numerous complete skulls have been found as well. Even with all the Triceratops fossils that have been found there is still much to learn.


Sources:
Dinosaur 1990 St. Martin's Press
Lessem, Don Dinosaurs A to Z 2003 scholastic ink
Big Book of Dinosaurs 2001 Running Press Book Publishers
wikipidia

Amargasaurus cazaui

Amargasaurus cazaui (La amarga)

Kingdom- Animelia
Phylum- Chordata
Class- Sauropsida
Superorder- Dinosauria
Order- Saurischia
Suborder- Sauropodomorpha
Clade-Sauropod
Superfamily- Diplodocioidea
Family Dicraeosauridae
Genus: Amargasaurus

Diet: Herbivore

Height: 10-14 feet

Length: 36-40 feet

Weight: 5-9 tons

Time of Habitation: Early Cretaceous period 132-127million years ago

Place of Habitation: South America

The Amargasaurus was found in Argentina in 1984, it was then named in 1991 by Salgado and Bonaparte. The Amargasaurus is built like most Sauropods with one major anatomical difference, it had two rows of extended vertebrate along it's back. These vertebrate probably formed a sail possibly even a double sail. This sail could have had numerous uses, some believe the sail may have been to deter predators from attacking it's long neck which would explain why the vertebrate are longest along the middle of the neck. The sail may have been a thermal regulator meaning that when Amargasaurus needed to heat up it could turn sideways to the sun and increase it's body temperature. If the Amargasaurus need to cool down it could shade it's sail and decrease it's body temperature. The sail may have been for attracting mates and for displays among males. If the sail was used for attracting mates then the males would have had a larger sail.

The Amargasaurus is known from an almost complete specimen that even had all of it's vertebrate! The skeleton does lack the frontal half of the skull as well as a majority of the tail. The skull is broad like that of modern day horses. Amargasaurus was extremely small for a sauropod. This small size indicates a life of grazing on the lower foliage of forest. There is debate as to whether or not it could rear up on it's hind legs like it's larger relatives. The Amargasaurus had teeth that specialized in chewing and grinding up tuff plants. It is thought that the Amargasaurus traveled in herds. I find this sailed sauropod extremely fascinating, I hope you enjoyed reading about it!

Deinonychus antirrhopus

Deinonychus antirrhopus (terrible claw)

Kingdom- Animalia
Phylum- Chordata
Order- Saurischia
Suborder- Theropoda
Clade- Eudramaeosauria
Family- Dromauosaurida
Subfamily- Velociraptorinae
Genus- Deinonychu

Diet: Meat

Length: 11.5 feet

Weight: 160 pounds

Time of Habitation: Early Cretaceous period 115-106 million years ago

Place of Habitation: United States


The first Deinonychus fossils were found in southern Montana near the town of Billings during 1931 by a team led by paleontologist Barnum Brown. Brown's main focus was excavating and preparing Tenontosaurus remains. However when he made his field report to the American Museum of Natural History he told of the discovery of a small cornivorous dinosaur skeleton near that of a Tenontosaurus.. Brown named his find "Dapatosaurus agilis" and prepared to describe it and have it put on display but he never completed his work. Deinonychus was later given it's name by Ostrum and Grant E. Meyer. By 1969 a number of bones were available but important ones were still missing such as the femurs, sacrum, sternum and several vertebrate.

Because of Ostrum's  research on the Deinonychus the debate about whether dinosaurs were warm-blooded or cold-blooded was ignited. Ostrom found similarities bettween the forefeet and hips of Deinonychus and those of modern day birds which caused him to revise his hypothesis that dinosaurs evolved into birds which is now a widely excepted theory. Because of the bird like anatomy Deinonychus is thought to have had feathers.

There is geological evidence that suggest that Deinonychus inhabited areas consisting of either floodplains or swamp like environments similar to today's Louisiana. Teeth of Deinonychus are a common find with Tenontosaurus skeletons.There is a Tenontosaurus humerus that has what might be Deinonychus bite marks on it! However a single Deinonychus could not kill a full grown Tenontosaurus which suggest pack hunting. Studies of modern archosaurs (birds and crocodiles point towards uncoordinated behavior within Deinonychus groups possibly even cannibalism at kill sites. On the other hand, a study of track sites point more towards coordinated pack activity.

Like Velociraptor ( a relative of Deinonychus) Deinonychus has large sickle-shaped claw that it could use during predatory behavior. The size and curvature of the claw differs from specimen to specimen. the younger specimens having a more curved claw than adults. There is speculation that this claw could be more curved in younger specimens to be more effective as a climbing utensil rather than being used for dealing lethal prey and as they got older it straightened for hunting. I hope you enjoyed reading about Deinonychus.



Sources:
wikipidia

Spinosaurus aegyptiacus

Spinosaurus aegyptiacus (spined lizard)

Kingdom- Animalia
Phylum- Chordata
Class- Spinosaurida
Order- Saurischia
Suborder- Theropoda
Clade- Megalosauria
Family- Spinosauridue
Subfamily- Spinosaurinae
Genus- Spinosaurus

Diet: Carnivore

Height: 17 to 21 feet

Length: 38 to 57 feet

Weight: 4 to 12 tons

Time of habitation: Through out the Cretaceous period 112 to 97 million years ago

Place of habitation: North Africa


The first Spinosaurus was found in Egypt in 1912 then named and described in 1915 by German paleontologist and aristocrat Ernst Stromer. Sadly however the original remains were destroyed in an Allied bombing run over Berlin.

Spinosaurus is said to have eaten large fish and lived in a similar fashion to modern day crocodiles, on both land and in the water. Spinosaurus gets it's name from the tall vertebrate along it's back that could extend upwards to lengths as tall as six feet! There is speculation that the sail could have been used as a thermal regulator. It would have released heat on hot days and absorbed heat on cool days. There is a possibility that the sail was used as a display to attract a mate as well as to intimidate other species of animal. There is slight speculation that the sail could instead have been a hump to allow for more muscle mass.

Unlike the T-rex the Spinosaurus had long powerful arms measuring five feet long. To date Spinosaurus is the largest theropod found, it is even larger than Gigantosaurus! Despite being the largest how ever, it had one of the lightest builds. The skull of the Spinosaurus resembles that of modern day crocodiles in shape. The teeth of the Spinosaurus are different from those of other theropods in that they are cone shaped and the serrations on it's teeth are considerably smaller.

Spinosaurus is thought to have more than likely eaten large fish and in times where aquatic resources were depleted, it is thought that the Spinosaurs scavenged and hunted prey both large and small. Despite major depiction as a biped it is sometimes thought to have been an occasional quadruped.
With all these advantages it is no wonder that Spinosaurus roamed the earth for 15 million years!

Gallimimus bullatus

Gallimimus bullatus (chicken mimic)

Kingdom- Animalia
Phylum- Chordata
Class- Archosauria
Order- Saurischia
Suborder- Theropoda
Superfamily-Ornithomimoidea
Family- Ornithamimidae

Diet: Omnivore

Height: 6.5 feet

Length: 26 feet

Weight: 500 pounds

Time of Habitation: Late Cretaceous Period

Place of Habitation: Mongolia




The first Gallimimus fossils were found in the Mongolian Gobi Dessert in August 1963 by a Professor Zofia Kielon-Jaworowska. She reported it two years later in 1965. It was not named or described until 1972 by paleontologist Rinchen Barsbold.

The ostrich-like Gallimimus had a long neck, tail and legs. It had a small head with large eyes and a beak that held no teeth. The Gallimimus did not have binocular vision like modern day birds due to it's eyes being located on the sides of the head.

The diet of Gallimimus caused controversy for a while. Some say that it used it's arms to rake away ground cover to expose small animals. In 2001 a Gallimimus specimen with soft tissue preservation was found. This specimen along with another fossilized skull had a keratinous beak  possessing vertical grooves projected from the upper mandible. These grooves are similar to the lamelle found in ducks. Ducks use these lamelle to filter through the water for small edible items.

It was later noted that strictly herbivorous turtles posses ridges on the inner surface of the beak similar to the grooves that Gallimimus possessed. Calculations of the amount of energy that could possibly be attained by filter feeding versus the possible amount of energy needed by a Gallimimus lead some to conclude that the Galimimus was more than likely an herbivore. However
more evidenve has been found that shows that Galimimus was an omnivore that fed of plants, eggs, insects and lizards.

The Gallimimus had a large brain based on mass and proportion meaning it was possibly very intelligent. It had large eyes meaning it might have been nocturnal. The Gallimimus was more than likely a very good runner possibly reaching speeds of up to 43 mph, the same as an ostrich's top speed! I hope you enjoyed meeting the prehistoric ostrich!






Sources:
Wikipidia
Wikia Dinopedia

Velociraptor mongoliensis

Velociraptor mongoliensis (swift thief)

Kingdom- Animalia
Phylum- Chordata
Class- Sauropsida
Super Order- Dinosauria
Order- Saurischia
Suborder- Theropoda
Family- Dromaeosauridae
Genus- Velociraptor

Diet: Carinivore

Height: 2.5 feet

Length: 5.9 feet

Weight: 40 pounds

Time of habitation: Late Cretaceous period- 83 to 70 million years ago

Place of habitation: Mongolia

The first Velociraptor fossil was a crushed but complete skull found in the Mongolia Gobi Dessert during 1922. The tail was stiff due to long bony projections (prezygapophyses) as well as ossified tendons on the underside of the tail. The stiff tail allowed the Velociraptor to balance very well enabling it to turn sharply at great speeds and twist in the air to slash out at prey.

The second claws on the back feet were long and sickle shaped claws measuring about 2.6 inches and was possibly used for slashing out and disemboweling prey. The "Fighting Dinosaur" specimen which was found in Mongolia shows a Protoceratops and a Velociraptor locked in combat. It shows the Velociraptor's claw embedded in the Protoceratops neck which hints at the claw being used to pierce vital organs. New evidence suggest that the Velociraptor's claw was used to climb the sides of it's prey.

It is unclear whether or not Velociraptors were pack hunters. The only solid evidence is a Chinese track way showing six individuals of the same species of dromaeosaurs traveling together with no evidence of collectively hunting together.

In September 2007 a Velociraptor forearm was found in Mongolia that had quill knobs on it! This is conclusive evidence that Velociraptor did indeed have feathers. Due to small arms though, the feathers did not allow the Velociraptor to fly.

A similarity between Volociraptors and modern day birds is that the Volociraptor folded it's wrist in like a bird folds in it's wings. When Velociraptor used it's claws it would twist them around like a bird does it's wings to fly. Some paleontologist believe that the Velociraptor would then use it's unfolded hands in a scissor like slashing motion to shred the prey's flesh.

Sources:
Wikipideia
DK Guide to Dinosaurs