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Description
Alberta, Western Canada - 75 million years ago and what it is appearing to become the end of the Late Cretaceous period and despite the arrival of the formation of the modern Rocky Mountains, the depositional Campanian landscape consisted of flat floodplain environments, an ideal habitat for browsing large megaherbivore Dinosaurs.

Prior to the Early Cretaceous, many new types of Dinosaurs have evolved and taken the roles of their predecessors. One of these new emerging groups are the hadrosaurids, an evolutionary successful group of herbivorous Ornithischian Dinosaur that will eventually spread across every continent, pole to pole and thriving in abundance and diverging into many unique forms.

Perhaps one of the reasons they were so successful was their unique ability to chew...Hadrosaurs had hundreds if not thousands of sets of teeth arranged in formation known as a dental battery. They also possessed a pleurokinetic hinge that allowed the cheek portion of the skull to move outwards when both jaws move vertically, therefore making a chewing motion of the jaws to quickly extract nutrients instead of requiring digestion to do so and gaining a maximum nutrition from eating.

Hadrosaurids were predominantly quadrupedal, as evident by the fact of their unique adaptations such as anterolateral process on the ulna, hoof like ungual morphology (ideal for weight bearing) and a ischium longer than the ilium. However they could rise on two legs if necessary.

Many species of Hadrosaurids held large exotic crests, like this male Corythosaurus and these two Parasaurolophus, which in the case of the 11.5 metre long Parasaurolophus case was a large extension of the nasal bone that extended behind the cranium. Parasaurolophus crests were sexually dimorphic, with the males having longer straighter extensions than their female counterparts that held slightly concaved ones.

These crests were vocal social sexual signalling display structures and aided with attracting mates with appearance and aided communication. Inside the hollow crests were a diverticula passageway of air tubes (with similarity with a Crumhorn air passageways). Help was provided by a vocal organ located between the lungs of the animal allowed calls to reach a frequency between 48-240 Hz. Such sounds would have sounded like www.youtube.com/watch?v=lBU6zf…

Along side these hadrosaurs is the large bulky nodosaurid Edmontonia which shows an impressive collection of spike-like and chailmail-like osteoderms for protection and defense.
This lone individual is a grazer and feeds on low lying vegetation like grass, surprisingly, grass did grow along side with the dinosaurs and became widespread at least in the Early Cretaceous

Another herbivorous Dinosaur with bony projections is the ceratopsian Styracosaurus, like hadrosaurs, ceratopsians have become dominant in numbers and in their ecological role and too have branched into many different variations in facial ornamentation along with immense body sizes but unlike their hadrosaur counterparts they tend to be restricted in the Northern Hemisphere. Something unsual about their anatomy is their posture, unlike other Dinosaurs with erect legs and crocodilians with a sprawling posture, ceratopsids's stance was somewhere intermediate, with a crouched neutral position and such stance has no modern analog.
The large front horn and extensive frill with epoccipitals (or spikes) of Styracosaurus were primarily for display to attract females and to distinct itself and avoid hybridisation with other sympatric species but like the osteoderms of Edmontonia, they could have also been used for defence.

Description
Alberta, Western Canada - 75 million years ago and what it is appearing to become the end of the Late Cretaceous period and despite the arrival of the formation of the modern Rocky Mountains, the depositional Campanian landscape consisted of flat floodplain environments, an ideal habitat for browsing large megaherbivore Dinosaurs.

Prior to the Early Cretaceous, many new types of Dinosaurs have evolved and taken the roles of their predecessors. One of these new emerging groups are the hadrosaurids, an evolutionary successful group of herbivorous Ornithischian Dinosaur that will eventually spread across every continent, pole to pole and thriving in abundance and diverging into many unique forms.

Perhaps one of the reasons they were so successful was their unique ability to chew...Hadrosaurs had hundreds if not thousands of sets of teeth arranged in formation known as a dental battery. They also possessed a pleurokinetic hinge that allowed the cheek portion of the skull to move outwards when both jaws move vertically, therefore making a chewing motion of the jaws to quickly extract nutrients instead of requiring digestion to do so and gaining a maximum nutrition from eating.

Hadrosaurids were predominantly quadrupedal, as evident by the fact of their unique adaptations such as anterolateral process on the ulna, hoof like ungual morphology (ideal for weight bearing) and a ischium longer than the ilium. However they could rise on two legs if necessary.

Many species of Hadrosaurids held large exotic crests, like this male Corythosaurus and these two Parasaurolophus, which in the case of the 11.5 metre long Parasaurolophus case was a large extension of the nasal bone that extended behind the cranium. Parasaurolophus crests were sexually dimorphic, with the males having longer straighter extensions than their female counterparts that held slightly concaved ones.

These crests were vocal social sexual signalling display structures and aided with attracting mates with appearance and aided communication. Inside the hollow crests were a diverticula passageway of air tubes (with similarity with a Crumhorn air passageways). Help was provided by a vocal organ located between the lungs of the animal allowed calls to reach a frequency between 48-240 Hz. Such sounds would have sounded like www.youtube.com/watch?v=lBU6zf…

Along side these hadrosaurs is the large bulky nodosaurid Edmontonia which shows an impressive collection of spike-like and chailmail-like osteoderms for protection and defense.
This lone individual is a grazer and feeds on low lying vegetation like grass, surprisingly, grass did grow along side with the dinosaurs and became widespread at least in the Early Cretaceous

Another herbivorous Dinosaur with bony projections is the ceratopsian Styracosaurus, like hadrosaurs, ceratopsians have become dominant in numbers and in their ecological role and too have branched into many different variations in facial ornamentation along with immense body sizes but unlike their hadrosaur counterparts they tend to be restricted in the Northern Hemisphere. Something unsual about their anatomy is their posture, unlike other Dinosaurs with erect legs and crocodilians with a sprawling posture, ceratopsids's stance was somewhere intermediate, with a crouched neutral position and such stance has no modern analog.
The large front horn and extensive frill with epoccipitals (or spikes) of Styracosaurus were primarily for display to attract females and to distinct itself and avoid hybridisation with other sympatric species but like the osteoderms of Edmontonia, they could have also been used for defence.