FOSSIL FARM MUSEUM

OF THE

FINGER

LAKES

 

 

 

 

 

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Millions of Years Ago (MYA)

The Cretaceous Heyday of Dinosaurs

146 to 65 Million Years Ago

     
 

RAPTOR

 

RAPTOR

A group of nasty predators, thriving in the late Cretaceous.  "Raptor" is a pop culture term, referring to dinosaurs, most notably the Velociraptor, Deinonychus, Utahraptor and other theropods such as Oviraptor.  Dromaeosauridae is the more acceptable (but less colorful) name for these bird-like structured theropod dinosaurs. They were small to medium-sized, possibly feathered carnivores. The informal term "raptor" (after Velociraptor), popularized by the film Jurassic Park will probably remain in popular usage. Technically, the name Dromaeosauridae means 'running lizards', from Greek dromeus meaning 'runner' and sauros meaning 'lizard'. 
"Theropods" refer to all two legged dinosaurs, with the word literally meaning "beast feet."  Raptors varied in size from that of a chicken, to somewhat larger than a human.  Based on size, weaponry including "slashing" claws, sharp serrated teeth and hollow bones (like the modern bird), we can assume that they were probably warm blooded, swift, extremely dangerous and possibly hunted in packs.

Tibia of Chirostenotes or Dromaeosaur

Channel Deposit (sub-surface) Garfield County, Montana Hell Creek Formation

Rib in Matrix

Lance Creek, Wyoming

Teeth

Hell Creek Channel Deposit, SE Montana

Vertebra from Small Raptor

Hell Creek, Montana

Crystallized Limb End Small Raptor

Hell Creek, Montana

Theropod Claws Unidentified Species

Channel Deposit, Eastern MT

EINIOSAURUS

 

 

EINIOSAURUS

 

Very rare, with partial fossil remains found only in the Two Medicine Formation North of Dupyer, Montana.  Probably the rarest example of the Ceratopsians.  In the same Ceratopsian family of dinosaurs as Triceratops, it was smaller, much odder in appearance and placement of horns.  Like most herbivores, it probably displayed herd behavior.  Displayed by few.  Owned by fewer.  Besides bone shape, it is also recognizable by the grey tint of bones due to the somewhat unique mineralization of Dupyer Montana area.

Ribs

Sacrum Vertebra, Upper Jaw Piece

Humerus

Teeth

All from Two Medicine Formation

North of Dupuyer, Montana.

Never found anywhere else.

TRICERATOPS

 

 

TRICERATOPS

A herbivore that could hold its own against the feared T-Rex and one of the two most popular dinosaurs of all time.  The function of their frills and three distinctive facial horns has long inspired debate. Although traditionally viewed as defensive weapons against predators, a new theory hypothesizes that these features were primarily used in courtship and dominance displays, much like the antlers.  You can decide for yourself.  Triceratops was about 30 feet long.  It's head, including the frill shield was up to ten feet in length.  Undoubtedly, it would have put up an excellent fight against any of the larger predators, including Tyrannosaurus Rex.  Somewhat resembling the modern Rhinoceros, the reptile/mammal similarity is an excellent example of what Paleontologists call "Convergent Evolution."  i.e.. If faced with similar environmental challenges, similar characteristics can develop over millions of years in the fight for species survival.  According to the existing fossil record, Triceratops was last of the giant dinosaurs to disappear in the great extinction.

 

Rib & Vert Process on reverse of Matrix

Lance Creek, WY

Nose Horn and Horn Bridge

Lance Creek, WY

Caudial (Tail Vertebra)

Channel Deposit (sub-surface) Garfield Cty, MT

Leg Bone Segment

Hell Creek.  Harding County SD

Hoof (Ungual)

Lance Creek, WY

Occipital (Rear) Skull Brain Case

Hell Creek.  West Central SD

Rib Head in Matrix

West Central, SD

Ceratopsian Frill

Lance Creek, WY

Beak and Snout

Lance Creek, WY

Frill & Skull

Lance Creek, WY

Jaw Sections 01

Hell Creek, N.W. SD

Jaw Sections 02

Hell Creek, N.W. SD

Teeth

Harding County, SD

TYRANNOSAURUS REX

 

TYRANNOSAURUS REX

Largest and most well known of the North American carnivores, it was probably both a predator and scavenger, although Paleontologists devoted to T-Rex lore will argue.  The skull alone could be as much as five feet in length, with a total length of about 40 feet.  Weight is approximated at six tons.  As an aside, Paleontologists can judge carnivore vs. herbivore bone derivation with about 90% accuracy. The internal structure of carnivore bones are usually "honeycombed" or granular in look, possibly caused by their diet.

Cervical (Neck) Vertebra

Hell Creek, N.W. SD

Centrum (Back) Vertebra Processes

Hell Creek, N.W. SD

Leg and Toe Bone

Baker, MT

Carnivorous Theropod Bone

Lance Creek, WY

Teeth

Buffalo SD & N. Baker Montana

Nano Tyrannosaurus Premaxillary Tooth

Tooth From Juvenile

Hell Creek Formation, MT

SPINOSAURUS

 

 

SPINOSAURUS

 

This genus was first known from Egyptian remains discovered in 1910. The original remains were destroyed in World War II, but additional skull material has come to light in recent years in North Africa.  Somewhat larger than Tyrannosaurus Rex, it's non-serrated teeth lead experts to believe that it might have lived on a diet of large fish. The large back "sail" has been hypothesized to have been used for either intimidation or courting, but we really don't know.

Teeth

Baharija Formation, Kem Kem Morocco

CARCHARODONTASAURUS

 

 

CARCHARODONTASAURUS

 

A carnivore, with enormous jaws and long, serrated teeth up to eight inches long.   Very similar to T-Rex and a bit larger, it is found in North Africa.  During the Cretaceous period, North West Africa possessed a lush, swampy environment, rather than the stark, dry, desert of today.  As with Spinosaurus (above), the original discovered remains were destroyed in World War II, but new finds were made in 1996.

Teeth

(Top) Tegana Formation,

Taouz, Morocco

(Bottom) Bahariji Formation,

Kem Kem Morocco

HYDROSAUR

 

 

HADROSAUR

 

A large herbivore nicknamed the "Duck Bill Dinosaur," it could walk on two or four extremities.  The most well known sub-species is Edmontosaurus.  Most common, varied, and well-adapted of the ornithopod (bird-hipped) dinosaurs.  This unique group of dinosaurs grew in sizes over 40 feet and probably weighed over 5 tons! In-depth studies of a variety of duckbill remains indicate that they walked predominantly on all fours but had the ability to stand on their hind legs.
 

Edmontosaurus Skin and Shoulder Blade from same animal

Skull Stripe, Vertebra, Foot Bones

Edmontosaurus Rib Head & End Tip

All from Hell Creek, N. Baker Montana

Edmontosdaurus Fibula

Hell Creek, MT

Edmontosauaurus Humerus Distal End

Hell Creek, MT

Edmontosaurus Femur End

Lance Creek, WY

Hadrosaur Tail Vertebra

Channel Deposit, Hell Creek MT

Hadrosaur Egg

Kaugo Formation, Xixia basin, Hunan China

ALBERTOSAURUS

 

ALBERTOSAURUS

Named after the western Alberta State of Canada where it is most frequently found.  A predator, smaller than T-Rex. Finding a large amount of remains together leads some to believe it might have displayed pack behavior.

Teeth

Foremost Beds, S.E. Alberta Canada

RICHARDOESTESIA

RICHARDOESTESIA

 

Richardoestesia is a medium sized theropod dinosaur from the late Cretaceous Period of North America.  Little is known of this creature.  Physiology is reconstructed from a single pair of lower jaw bones and a large number of isolated teeth. The jaws are slender and rather long but the teeth are small and finely serrated. It has been suggested that Richardoestesia was a fish eater, but most likely, it was a hunter of opportunity. Because so little is known of the animal, its relationships are unclear. However, the jaws resemble Archaeopteryx, Troodontidae and some Dromaeosauridae, in having a strong groove on the lateral surface.  It is estimated to have weighed approximately 220 pounds.

 

Teeth

Hell Creek, Powder River County MT

 

 

OVIRAPTOR

 

OVIRAPTOR

Late Cretaceous

A small dinosaur originally found in Mongolia, its name means "Egg Seizer."  Originally discovered lying on a group of eggs, it was hypothesized this dinosaur was an egg thief.  This theory has been subsequently disproven to some extent although eggs of other species might have been a portion of its diet.   Birdlike in physiology, it is probably not an early avian.  On the other hand, it is felt to have been a meat eater.  A member of the suborder Theropoda, Oviraptor grew to a length of up to 2.7 m (9 ft). It walked upright, balancing itself with its heavy tail, and had long, powerful forelimbs.  This dinosaur had a short head and a strong, curved, toothless beak. Bony prongs inside its mouth appear similar to the throat tooth of egg-eating snakes but we can only speculate.  Oviraptor probably lived near lakes where it may have fed on freshwater mussels, crushing the shells with its powerful beak. This dinosaur had a hornlike crest on its nose.

 

Claw

Hell Creek Formation, Montana

Egg Segment

Nanxiong Formation, Guangdong Provice China

 

TROODON

TROODON

Troodon is a genus of relatively small, bird-like dinosaur from the Late Cretaceous, 75-65 mya. Discovered in 1855, it was among the first dinosaurs found in North America. Its name  is Greek for "wounding tooth", referring to the dinosaur's teeth, which bore prominent serrations.  At the very least, it was omnivorous.  Troodon was a small dinosaur, around 6.5 feet in length, 3 feet tall, and weighed about 130 pounds. It had very long, slender limbs, suggesting that the animal was able to move quickly. It had large, retractable sickle-shaped claws on its second toes, which were raised off the ground when running.

Tooth

Dinosaur Park Formation

S.E. Alberta Canada

CAMPTOSAURUS

 

CAMPTOSAURUS

A herbivore of the late Jurasic, early Cretaceous.  The name means "bent lizard," because, when standing on all fours, its body must have been arched.  Smaller than the Hydrosaur that appear later, they have many physical similarities.

 

Leg Bones

Morrison Formation, Big Horn Basin WY

THESCELOSAURUS

THESCELOSAURUS

Thescelosaurus meaning marvelous Lizard in Greek, was a genus of small ornithopod dinosaur that appeared at the very end of the Late Cretaceous period in North America.
Skeletons and skulls, indicate it grew to between 8 to 13 feet in length on average. It had sturdy hind limbs, small wide hands, and a head with an elongate pointed snout. This genus of dinosaur is regarded as a specialized herbivore, but might have been an omnivore.
The genus attracted media attention in 2000, when a specimen unearthed in 1993 in South Dakota was interpreted as including a fossilized heart, although there is much debate as to whether or not it really was a heart.

Various Teeth

Hell Creek, Montana

Premaxilla +7 Maxilla back. Same animal

Powder River County, MT

 

ANKYLOSAURUS

 

ANKYLOSAURUS

 

Although a complete skeleton has not been discovered, Ankylosaurus is often considered the archetypal armored dinosaur.  The largest was Euoplocedphalus.  This herbivore's defense was an armored body and massive bony tail club.  Although a reptile, this creature shared physical qualities with the giant mammalian Glyptodonts and Armadillos of the Pleistocene, some 65 million years later.  This "convergent evolution" may be due to similar environmental conditions and defense needs, or just coincidence. 

Teeth & Armor Plate Segment

1 Pre-Molar - Lance Creek Wyoming

2 Molars - Judith River Form. N. Lewistown MT

Scute Section - Harding County, SD

Armor Plate (Scute) Complete

Judith River Formation, Alberta Canada

Armor Plate (Scute) Large

Hell Creek, Montana

 

AUBLYSODON

 

AUBLYSODON

 

Very little information exists, other than the many similar teeth found in several areas of the United states and Asia in late Cretaceous period strata. It may be that this is not a distinct species at all and the teeth come from a juvenile tyrannosaurid.   Your guess is as good as anyone else's.

 

Tooth

Hell Creek, Montana

PACHYCEPHALOSAURUS

PACHYCEPHALOSAURUS

Pachycephalosaurus means "thick headed lizard." It lived during the Late Cretaceous Period  of what is now North America. Remains have been excavated in Montana, South Dakota, and Wyoming. It was a herbivorous or omnivorous creature which is only known from a single mostly complete skeleton, almost complete skulls, a few extremely thick skull roofs and assorted, incomplete fossil remains.  It is estimated to have been 16 feet in length and to have weighed some fifteen hundred pounds.  Large bone segments are rare.  Some Paleontologists have hypothesized that Pachycephalosaurus is the same species as the similar and equally rare Stygimoloch spinifer. Nobody really knows for sure. 

Femur Leg Bone, Left Side

Lance Creek Wyoming

Skull Knob & Spike

Lance Creek, Wyoming

Tooth

Butte County, South Dakota

 

PLESIOSAUR

PLESIOSAUR

(Jurassic-Cretaceous)

Plesiosaurs means "near lizard."  It was a carnivorous, aquatic, non-dinosaur reptile.  Many have been found in England, some of them virtually complete, and new discoveries are made frequently.  Some grew to sixty feet in length.  Paleontologists have joked about this strange reptile, calling it a large snake, strung through the shell of a giant turtle.  Naturally, this deadly predator was neither.

Vertebra with Process & Pectoral Bone

North Yorkshire Coast, UK

Main Paddle Bone with Vertebra

Found by Michelle Keating

Portland Dorset UK, Aug 2008

Tooth

Khouribgha, Morocco

 

REBBACHISAURUS

REBBACHISAURUS

Rebbachisaurus is a genus of sauropod dinosaurs, up to sixty-eight feet long.  It lived in the Early Cretaceous period, about 99 million years ago. This massive four-legged plant-eating animal had a small head, a long, graceful neck and a whip-like tail. Rebbachisaurus is distinguished from other sauropods by its unusually tall, ridged back.  It has the typical "chisel" tip teeth of large herbivores, for stripping leaves off branches.

Tooth

Kem-Kem Morocco

OMITHOPSIS humerocristatus

 

SAUROPODS of the KIMMERIDGE CLAY DEPOSITS, PORTLAND HARBOR UK

(Late Jurassic through Cretaceous)

 

Popularly and somewhat incorrectly called "The Jurassic Coast," this area is rather rich in four legged giant Sauropods.  Sauropoda or the Sauropods are notable for the enormous sizes attained by some species.  The group includes many of the largest animals to have ever lived on land. Well-known genera include Apatosaurus (formerly known as Brontosaurus), Brachiosaurus and Diplodocus. One of the rarest is Omithopsis humerocristatus, nicknamed "The Portland Dinosaur," of which barely more than vertebra have been found.  Based on analysis, it is fair to assume that it was rather like Diplodocus or Brachiosaurus, possibly smaller at 50 feet in length.  Like the other large Sauropods, it was vegetarian, but sufficiently large for adults to keep Theropod predators at bay.

Omithopsis humerocristatus Tail Vertebra

Kimmeridge Clay Deposits,

Portland Harbor, UK

TITANOSAUR

 

TITANOSAUR

 

A diverse group of herbivore sauropod dinosaurs, which included Saltasaurus and Isisaurus. It includes some of the heaviest creatures ever to walk the earth, some of which might have weighed up to 100 tons. Others were significantly smaller.  Because of their immense size, they were named after the mythological Titans.  Titanosaurs had small heads and a crest formed by nasal bones.  Legs were somewhat short for their size, with broad sided bodies.  They were widespread in Southern Continents.  The Rio Colorado Formation (now called a Sub Group) in North West Argentina has proven rich in Cretaceous dinosaur fossils between 83-75 million years old.

Egg

Rio Colorado Formation

North West Patagonia, Argentina

MOSASAUR

 

MOSASAUR

 

Some paleontologists consider this vicious, reptilian marine predator to be a relative of sea-snakes, but nobody really knows.  Mosasaurs breathed air and were powerful swimmers, well-adapted to living in the warm, shallow seas, prevalent during the Late Cretaceous Period. Mosasaurs were so well adapted to this environment that they gave birth to live young, rather than return to the shore to lay eggs, as sea turtles do.  Some were as much as thirty five-feet long.

 

Vertebras+Squalicorax shark tooth Matrix

Niobrara Formation, Western Kansas

Tooth with Root in Matrix

Atlas Mountains, Morocco

Vertebra

Ozan Formation, Taylor Shale Deposits N.E. TX

Flipper Joint

Pierre Shale Deposits, W. Kansas

Ribs in Shale

Alberta, Canada

 

CROCODILUS cf. SPENCERI

a.k.a. KENTISUCHUS

CROCODILES OF THE

CRETACEOUS

 

Crocodiles are among the most successful of reptiles, surviving several mass extinctions.  This is probably due to their living in an aquatic environment, more immune to the climatic change and pollution that doomed the land reptiles.

 Phobosuchus riograndensis was the hugest discovered to date, living about 70 million years ago in the late Cretaceous. It was about 50 feet long, with a head extending some 6 feet in length.
Fossilized remains of Phobosuchus have been found in Texas which was under water during the Cretaceous. Crocodiles are saltwater reptiles, venturing into coastal marshes, lakes, and rivers.

 

Other Cretaceous crocodiles were also large.

One was Crocodilus cf. spenceri, now renamed to Kentisuchus.  Discovered in the Tegana Formation of the Kem Kem phosphate mine region, K’Sar-es-Souk Province, Khouribga, Morocco.  They weighed 5-10 tons and attained a length of 25-40 feet with a four to five foot skull. Land vertebrates including young or small dinosaurs may have been additional victims.  Primarily found in the late Cretaceous (75-65 MYA), examples have been found in the early Eocene (54-45 MYA)

Many early Crocodiles can be recognized by the large bulbous front snout and relatively narrow jaw. 

The last remaining descendant of these Cretaceous Crocodilia is the endangered to near extinct Indian Gharial.

 

Top skull in matrix of Crocodilus cf. spenceri  a.k.a. Kentisuchus

Tegana Formation of the Kem Kem phosphate mine region, K’Sar-es-Souk Province, Khouribga, Morocco

 

     
 

 

 

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