PALEO MONT PARK HADROSAURIDS

Hadrosaurids are divided into two groups Hadrosaurines and Lambeosaurines. Hadrosaurines have no crests on their head like that of Lambeosaurines.

Hadrosaurines

Anatosaurus copei 'giant duck lizard' Plant eater.70-65 MYA Late Cretaceous. 30-40 feet long 7-8 feet high at hips. 3 tons, A relative of Edmontosaurus. Has a long and broad 'duckbill'. Front portion of skull lacks teeth. More slender limbs then other hadrosaurs. A.longiceps is 40-45 feet long 3- 4 tons. Based on a jawbone.

Hadrosaurid rasp like teeth on lower jaw.

Edmontonsaurus regalis 'reptile from Edmonton Formation in Canada'

Edmontosaurus in Fort Peck Dam Museum, display done by Nate Murphy

E. annectens Hell Creek Formation apx 70-65 MYA. Plant eater. 33-42 feet long. 73-76 MYA Late cretaceous. Closest relative is Anatosaurus. Has large hindlegs with a flexible neck and tail. Several skeletons have been found. Skin impressions have been found that show it had thin and leather like skin with horny bumps. A small frill went down the back.

Edmontonsaurus skeleton.

Edmontonsaurus skull.

Prosaurolophus maximus 'before crest lizard' Plant eater. 26 feet long. 77-73 feet long. Looked similar to Saurolophus but smaller, shorter bill and no crest.

Brachylophosaurus candensis 'short ridged reptile'

Brachylophosaurus in Philips County Museum

Plant eater. 23 feet long. 75 MYA Late Cretaceous. Unusual charasitic's is a nasal spike, thought to be used for head pushing contests. Have longer limbs then other hadrosaurs. B.goodwini discovered in MT in 1981, this is different from B.candensis from skull depressions. Maybe one species, male and female.

Maisaurus peeblesorum 'good mother lizard' Plant eater, 26 feet long. Close relative is Prosaurolophus. 77-73 MYA Late Cretaceous. Had a long wideface with a short wide bill. Skull is 32 inches long and 13.5 inches high. The baby Maisaura grew from 13 inches to 3 feet at the nest site. They were the first baby dinosaurs too be found in the United States, the only other site was in Mongolia with a Protoceratops eggs. Found in Montana in 1978 by Laurie Trexler, named by Jack (John) Horner and associate Robert Makela. They had found many Maisaura eggs nesting sites or nest colonies.

Lambeosaurines

They have large olfactory senses. They are also thought to deal with species identification.

Corythosaurus casuarius 'Corinthian helmet reptile'

Plant eater. 76-72 MYA late Cretaceous. 33 feet long. Closest relative of Lambeosaurus. Late cretaceous. Has large round crest on head. That has complex respiratory system with the breathing tubes from the nostrils to the back of the throat. Left and right nasal passages meet on top of the skull.
<-------------Corythosaurus skull

Lambeosaurus magnicristatus 'Lambe's reptile' Plant eater. 30 feet long, 8 feet high at the hips. 76-65 MYA Late Cretaceous. Has a hollow crest on skull. Males have a larger crest then females. Skin was thin.

Parasauralophus walkeri'by lizard crest' Herbavoire. 30 feet long. Late cretaceous. Has a long tube that is over 3 feet long. Strong jaw muscles to chew up the tough foliage it ate. Had strong front and back legs. Males have longer crests...while females have short crests. Have large vertebrae for muscle attachment of hip and leg muscles. Male Parasauralophus.---------->

Hypacrosaurus altispinus 'very high spine lizard' Plant eater. 30 feet long. 72-70 MYA Late cretaceous. Skull is similar to Corythosaurus, but not as rounded. Had about 40 rows of teeth and a short toothless bill. Had a ridged back. Long spines that gave it a humplike look.

This is a Hadrosaurid egg.

Go to Protoceratopsids

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