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Description
Here is a sketch consisting of a few dinosaur species from Cretaceous North America, specifically Alaska and Canada, so I figured I can give some info on each of these animals.

Nanuqsaurus is a genus of carnivorous tyrannosaurid theropod known from the Late Cretaceous period Prince Creek Formation of the North Slope of Alaska, United States. It contains a single species, Nanuqsaurus hoglundi, known only from a partial skull and multiple undescribed postcranial and teeth elements. Nanuqsaurus DMNH 21461 was estimated at 5-6 meters (16-20 feet) long at naming, half the length of Tyrannosaurus. It was estimated at 500-900 kilograms (1100-2000 pounds). This small size was postulated to be an adaptation of its northern environment. However, later studies found its size is unfounded, and was likely similar in size to other North American tyrannosaurids, like Albertosaurus, based on undescribed adult teeth and postcrania. A ridge on the skull shows it was related to Tyrannosaurus. The reconstructed skull is 60-70 centimeters (24-28 inches) long. As a tyrannosaurine, it is diagnosed as a thin, rostrally forked and median spur on the fused parietals, who overlap and separates the frontals within the sagittal crest, frontals with a long and rostrally-pointed process that separates from the prefrontal and lacrimal facets and the first 2 dentary teeth are smaller than the teeth to their posterior. Some estimates state it is 7 meters long, comparable to a juvenile Tarbosaurus. According to paleontologists, about 70 million years ago northern Alaska was a part of an ancient subcontinent called Laramidia and experienced cold weather and extreme changes in the amount of daylight during the year, with seasons in which food was not readily available. Prey availability likely would have increased substantially during the summer, but then declined in the dark winter, leaving predators with little to eat. Fiorillo and Tykoski stated that this lack of food might explain Nanuqsaurus's unusually small size for an advanced tyrannosaur, as a large animal cannot survive on scarce resources. Nanuqsaurus may have evolved a smaller size because of the decrease in year-round food supply, caused by the colder temperatures. In contrast, it was also found that the normal length of Troodon was 50% larger in Alaska compared to more southerly areas, possibly because a larger eye size allowed it to hunt more effectively in low-light conditions.

Troodon (previously Troödon) is a dubious and potentially invalid genus of troodontid dinosaur that lived in North America during the Late Cretaceous (though, to be honest, I still think Troodon existed as a species, albeit native to what is now the Prince Creek Formation). With a (relatively) large brain for its body size, Troodon may have been one of the most intelligent dinosaurs known. It may have possessed intelligence similar to most modern-day birds. Troodon had large eyes that bore the ability to focus on objects in front of them, which made hunting for the dinosaur easier. Troodon may have been nocturnal, because its big eyes likely helped vision in the dark. Troodon was described based on a single tooth, which are smaller than a United States dime. They bear prominent serrations on their backwards-facing sides. Based on other troodontids, Troodon had a long tail, which supported a fan of feathers, clawed wings, long legs with small sickle claws and a compact head filled with teeth. The teeth shape compare well to herbivorous reptiles, possibly making Troodon an omnivore. The approximated length of Troodon is around 7.9 feet long, standing 3-6 feet tall in height, with estimates of its weight falling at around 110 pounds. The animal in the drawing is most likely Stenonychosaurus, which is a synonym of Troodon inequalis. (Note: I based the colors and patterns on the Blue Jay.)

Ornithomimus is a genus of ornithomimid dinosaur from the Late Cretaceous Period of what is now North America. Ornithomimus was a swift bipedal theropod which fossil evidence indicates was covered in feathers, equipped with a small toothless beak that may indicate an omnivorous diet. It is usually classified into two species: the type species, Ornithomimus velox, and a referred species, Ornithomimus edmontonicus. O. velox was named in 1890 by Othniel Charles Marsh on the basis of a foot and partial hand from the late Maastrichtian-age Denver Formation of Colorado, United States. Another seventeen species have been named since, though most of them have subsequently been assigned to new genera or shown to be not directly related to Ornithomimus velox. The best material of species still considered part of the genus has been found in Alberta, Canada, representing the species O. edmontonicus, known from several skeletons from the early Maastrichtian Horseshoe Canyon Formation. Additional species and specimens from other formations are sometimes classified as Ornithomimus, such as Ornithomimus samueli (alternately classified in the genera Dromiceiomimus or Struthiomimus) from the earlier, Campanian-age Dinosaur Park Formation of Alberta. Like other ornithomimids, species of Ornithomimus are characterized by feet with three weight-bearing toes, long slender arms, and long necks with birdlike, elongated, toothless, beaked skulls. They were bipedal and superficially resembled an ostrich. They would have been swift runners. They had very long limbs, hollow bones, and large brains and eyes. The brains of ornithomimids in general were large for non-avialan dinosaurs, but this may not necessarily be a sign of greater intelligence; some paleontologists think that the enlarged portions of the brain were dedicated to kinesthetic coordination. The bones of the hands are remarkably sloth-like in appearance, which led Henry Fairfield Osborn to suggest that they were used to hook branches during feeding. Ornithomimus differ from other ornithomimids, such as Struthiomimus, in having shorter torsos, long slender forearms, very slender, straight hand and foot claws and in having hand bones (metacarpals) and fingers of similar lengths. The two Ornithomimus species today seen as possibly valid differ in size. In 2010 Gregory S. Paul estimated the length of O. edmontonicus at 3.8 m (12 ft), its weight at 170 kilograms (370 lb). One of its specimens, CMN 12228, preserves a femur (thigh bone) 46.8 centimetres (18.4 in) long. O. velox, the type species of Ornithomimus, is based on material of a smaller animal. Whereas the holotype of O. edmontonicus, CMN 8632, preserves a second metacarpal eighty-four millimetres long, the same element with O. velox measures only fifty-three millimetres.

Centrosaurus is a genus of herbivorous ceratopsian dinosaur from the Late Cretaceous of Canada. Their remains have been found in the Dinosaur Park Formation, dating from 76.5 to 75.5 million years ago. The first Centrosaurus remains were discovered and named by paleontologist Lawrence Lambe in strata along the Red Deer River in Alberta, Canada. The name Centrosaurus means "pointed lizard" (from Greek kentron, κέντρον, "point or prickle" and sauros, σαῦρος, "lizard"), and refers to the series of small hornlets placed along the margin of their frills, not to the nasal horns (which were unknown when the dinosaur was named). The genus is not to be confused with the stegosaur Kentrosaurus, the name of which is derived from the same Greek word. Later, vast bonebeds of Centrosaurus were found in Dinosaur Provincial Park, also in Alberta. Some of these beds extend for hundreds of meters and contain thousands of individuals of all ages and all levels of completion. Scientists have speculated that the high density and number of individuals would be explained if they had perished while trying to cross a flooded river. A discovery of thousands of Centrosaurus fossils near the town of Hilda, Alberta, is believed to be the largest bed of dinosaur bones ever discovered. The area is now known as the Hilda mega-bonebed. The massive bodies of Centrosaurus were borne by stocky limbs, although at up to 5.5 metres (18 ft) they were not particularly large dinosaurs. Like other centrosaurines, Centrosaurus bore single large horns over their noses. These horns curved forwards or backwards depending on the specimen. Skull ornamentation was reduced as animals aged. The frill was relatively short compared to the total skull length, and could grow to over half a meter (68.8 cm) long in the oldest and largest adults.

Brachylophosaurus was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana, the Wahweap Formation of Utah and the Oldman Formation of Alberta, living about 81-76.7 million years ago. Brachylophosaurus is notable for its bony crest, which forms a horizontally flat, paddle-like plate over the top of the rear skull. Some, depending on their age, had crests that covered nearly the entire skull roof, while others had shorter, narrower crests. Some researchers suggest it was used for pushing contests, but it may not have been strong enough for this. Other notable features are a relatively small head, the unusually long lower arms and the beak of the upper jaw being wider than other hadrosaurs of that time. Apart from the above, Brachylophosaurus was a typical hadrosaur which reached an adult length of at least 9 metres (30 ft). In 2010, Gregory S. Paul estimated maximum length at 11 metres (36 ft) resulting in weight of 7 metric tons (7.7 short tons). Like other hadrosaurs, Brachylophosaurus had features like cheeks to keep fodder in the mouth and dental batteries with hundreds of stacked teeth. These teeth could be used to chew efficiently, a feature rare among reptiles, but common among some cerapodan ornithischian dinosaurs like Brachylophosaurus. A 2008 study conducted on the famous dinosaur mummy Leonardo found that Brachylophosaurus had a diet that consisted of leaves, conifers, ferns, and flowering plants like magnolias. The study also found that Brachylophosaurus was a generalist herbivore; being both a browser and a grazer, but it did more of the former rather than the latter due to the contents found in its stomach.

Pachyrhinosaurus is an extinct genus of centrosaurine ceratopsid dinosaur from the Late Cretaceous period of North America around 71 million to 67 million years ago. The first examples were discovered by Charles M. Sternberg in Alberta, Canada, in 1946, and named in 1950. Pachyrhinosaurus was both large and quadrupedal. It grew to 6 meters (20 feet) in length and weighed about 1,800 kg (almost 2 tons). Size estimates for the largest Pachyrhinosaurus species, P. canadensis indicate lengths of 6–8 meters (19.7–26.2 ft) and a weight of 3–3.6 tons (3.3–4.0 tons). An herbivore, Pachyrhinosaurus used the batteries of teeth in its jaws to slice open and consume plants. Some of its horns grew in unicorn fashion between and slightly behind the eyes, whereas others decorated the top edge of the frill. Pachyrhinosaurus also sported thickened knobs of bone; the largest of these knobs covered the top of the nose. The function of these knobs, horns, and frill is unknown, but they may have been used for species recognition, competition between males, or defense against predators. It is closely related to Styracosaurus and Centrosaurus and more distantly related to Triceratops. Like other ceratopsids, it possessed a prominent skull characterized by a narrow but massive beak and a bony frill. The Greek name Pachyrhinosaurus means “reptile with a thick nose.” Specimens of Pachyrhinosaurus are known from bone beds in southern Alberta, Can., and the North Slope of Alaska, U.S. In both locations, the bone beds contain juveniles and adults, which suggests that this dinosaur may have provided parental care by herding. Although average global temperatures were much warmer during the Cretaceous Period than they are today, Pachyrhinosaurus populations in Alaska and northern Canada did have to contend with months of winter darkness. It remains unknown whether they migrated south during the Alaskan winter.

Lambeosaurus is a genus of hadrosaurid dinosaur that lived about 75 million years ago, in the Late Cretaceous period of North America. This bipedal/quadrupedal, herbivorous dinosaur is known for its distinctive hollow cranial crest, which in the best-known species resembled a hatchet. Material relevant to the genus was first named by Lawrence Lambe in 1902. Over twenty years later, the modern name was coined in 1923 by William Parks, in honour of Lambe, based on better preserved specimens. The genus has a complicated taxonomic history, in part because small-bodied crested hadrosaurids now recognized as juveniles were once thought to belong to their own genera and species. Currently, the various skulls assigned to the type species L. lambei are interpreted as showing age differences and sexual dimorphism. Lambeosaurus was closely related to the better known Corythosaurus, which is found in slightly older rocks, as well as the less well-known genera Hypacrosaurus and Olorotitan. All had unusual crests, which are now generally assumed to have served social functions like noisemaking and recognition. Lambeosaurus, best known through L. lambei, was quite similar to Corythosaurus in everything but the form of the head adornment. Compared to Corythosaurus, the crest of Lambeosaurus was shifted forward, and the hollow nasal passages within were at the front of the crest and stacked vertically. It also can be differentiated from Corythosaurus by its lack of forking nasal processes making up part of the sides of the crest, which is the only way to tell juveniles of the two genera apart, as the crests took on their distinctive forms as the animals aged. Lambeosaurus was like other hadrosaurids, and could move on both two legs and all fours, as shown by footprints of related animals. It had a long tail stiffened by ossified tendons that prevented it from drooping. The hands had four fingers, lacking the innermost finger of the generalized five-fingered tetrapod hand, while the second, third, and fourth fingers were bunched together and bore hooves, suggesting the animal could have used the hands for support. The fifth finger was free and could be used to manipulate objects. Each foot had only the three central toes. The most distinctive feature, the crest, was different in the two well-known species. In L. lambei, it had a hatchet-like shape when the dinosaur was full-grown, and was somewhat shorter and more rounded in specimens interpreted as females. The "hatchet blade" projected in front of the eyes, and the "handle" was a solid bony rod that jutted out over the back of the skull. The "hatchet blade" had two sections: the uppermost portion was a thin bony "coxcomb" that grew out relatively late in life, when an individual neared adulthood; and the lower portion held hollow spaces that were continuations of the nasal passages. Large adult specimens of Lambeosaurus have been estimated to be around 7 m (23 ft) long. Impressions of the scales are known for several specimens; a specimen now assigned to L. lambei had a thin skin with uniform, polygonal scutes distributed in no particular order on the neck, torso, and tail. Similar scalation is known from the neck, forelimb, and foot of a specimen of L. magnicristatus.

Description
Here is a sketch consisting of a few dinosaur species from Cretaceous North America, specifically Alaska and Canada, so I figured I can give some info on each of these animals.

Nanuqsaurus is a genus of carnivorous tyrannosaurid theropod known from the Late Cretaceous period Prince Creek Formation of the North Slope of Alaska, United States. It contains a single species, Nanuqsaurus hoglundi, known only from a partial skull and multiple undescribed postcranial and teeth elements. Nanuqsaurus DMNH 21461 was estimated at 5-6 meters (16-20 feet) long at naming, half the length of Tyrannosaurus. It was estimated at 500-900 kilograms (1100-2000 pounds). This small size was postulated to be an adaptation of its northern environment. However, later studies found its size is unfounded, and was likely similar in size to other North American tyrannosaurids, like Albertosaurus, based on undescribed adult teeth and postcrania. A ridge on the skull shows it was related to Tyrannosaurus. The reconstructed skull is 60-70 centimeters (24-28 inches) long. As a tyrannosaurine, it is diagnosed as a thin, rostrally forked and median spur on the fused parietals, who overlap and separates the frontals within the sagittal crest, frontals with a long and rostrally-pointed process that separates from the prefrontal and lacrimal facets and the first 2 dentary teeth are smaller than the teeth to their posterior. Some estimates state it is 7 meters long, comparable to a juvenile Tarbosaurus. According to paleontologists, about 70 million years ago northern Alaska was a part of an ancient subcontinent called Laramidia and experienced cold weather and extreme changes in the amount of daylight during the year, with seasons in which food was not readily available. Prey availability likely would have increased substantially during the summer, but then declined in the dark winter, leaving predators with little to eat. Fiorillo and Tykoski stated that this lack of food might explain Nanuqsaurus's unusually small size for an advanced tyrannosaur, as a large animal cannot survive on scarce resources. Nanuqsaurus may have evolved a smaller size because of the decrease in year-round food supply, caused by the colder temperatures. In contrast, it was also found that the normal length of Troodon was 50% larger in Alaska compared to more southerly areas, possibly because a larger eye size allowed it to hunt more effectively in low-light conditions.

Troodon (previously Troödon) is a dubious and potentially invalid genus of troodontid dinosaur that lived in North America during the Late Cretaceous (though, to be honest, I still think Troodon existed as a species, albeit native to what is now the Prince Creek Formation). With a (relatively) large brain for its body size, Troodon may have been one of the most intelligent dinosaurs known. It may have possessed intelligence similar to most modern-day birds. Troodon had large eyes that bore the ability to focus on objects in front of them, which made hunting for the dinosaur easier. Troodon may have been nocturnal, because its big eyes likely helped vision in the dark. Troodon was described based on a single tooth, which are smaller than a United States dime. They bear prominent serrations on their backwards-facing sides. Based on other troodontids, Troodon had a long tail, which supported a fan of feathers, clawed wings, long legs with small sickle claws and a compact head filled with teeth. The teeth shape compare well to herbivorous reptiles, possibly making Troodon an omnivore. The approximated length of Troodon is around 7.9 feet long, standing 3-6 feet tall in height, with estimates of its weight falling at around 110 pounds. The animal in the drawing is most likely Stenonychosaurus, which is a synonym of Troodon inequalis. (Note: I based the colors and patterns on the Blue Jay.)

Ornithomimus is a genus of ornithomimid dinosaur from the Late Cretaceous Period of what is now North America. Ornithomimus was a swift bipedal theropod which fossil evidence indicates was covered in feathers, equipped with a small toothless beak that may indicate an omnivorous diet. It is usually classified into two species: the type species, Ornithomimus velox, and a referred species, Ornithomimus edmontonicus. O. velox was named in 1890 by Othniel Charles Marsh on the basis of a foot and partial hand from the late Maastrichtian-age Denver Formation of Colorado, United States. Another seventeen species have been named since, though most of them have subsequently been assigned to new genera or shown to be not directly related to Ornithomimus velox. The best material of species still considered part of the genus has been found in Alberta, Canada, representing the species O. edmontonicus, known from several skeletons from the early Maastrichtian Horseshoe Canyon Formation. Additional species and specimens from other formations are sometimes classified as Ornithomimus, such as Ornithomimus samueli (alternately classified in the genera Dromiceiomimus or Struthiomimus) from the earlier, Campanian-age Dinosaur Park Formation of Alberta. Like other ornithomimids, species of Ornithomimus are characterized by feet with three weight-bearing toes, long slender arms, and long necks with birdlike, elongated, toothless, beaked skulls. They were bipedal and superficially resembled an ostrich. They would have been swift runners. They had very long limbs, hollow bones, and large brains and eyes. The brains of ornithomimids in general were large for non-avialan dinosaurs, but this may not necessarily be a sign of greater intelligence; some paleontologists think that the enlarged portions of the brain were dedicated to kinesthetic coordination. The bones of the hands are remarkably sloth-like in appearance, which led Henry Fairfield Osborn to suggest that they were used to hook branches during feeding. Ornithomimus differ from other ornithomimids, such as Struthiomimus, in having shorter torsos, long slender forearms, very slender, straight hand and foot claws and in having hand bones (metacarpals) and fingers of similar lengths. The two Ornithomimus species today seen as possibly valid differ in size. In 2010 Gregory S. Paul estimated the length of O. edmontonicus at 3.8 m (12 ft), its weight at 170 kilograms (370 lb). One of its specimens, CMN 12228, preserves a femur (thigh bone) 46.8 centimetres (18.4 in) long. O. velox, the type species of Ornithomimus, is based on material of a smaller animal. Whereas the holotype of O. edmontonicus, CMN 8632, preserves a second metacarpal eighty-four millimetres long, the same element with O. velox measures only fifty-three millimetres.

Centrosaurus is a genus of herbivorous ceratopsian dinosaur from the Late Cretaceous of Canada. Their remains have been found in the Dinosaur Park Formation, dating from 76.5 to 75.5 million years ago. The first Centrosaurus remains were discovered and named by paleontologist Lawrence Lambe in strata along the Red Deer River in Alberta, Canada. The name Centrosaurus means "pointed lizard" (from Greek kentron, κέντρον, "point or prickle" and sauros, σαῦρος, "lizard"), and refers to the series of small hornlets placed along the margin of their frills, not to the nasal horns (which were unknown when the dinosaur was named). The genus is not to be confused with the stegosaur Kentrosaurus, the name of which is derived from the same Greek word. Later, vast bonebeds of Centrosaurus were found in Dinosaur Provincial Park, also in Alberta. Some of these beds extend for hundreds of meters and contain thousands of individuals of all ages and all levels of completion. Scientists have speculated that the high density and number of individuals would be explained if they had perished while trying to cross a flooded river. A discovery of thousands of Centrosaurus fossils near the town of Hilda, Alberta, is believed to be the largest bed of dinosaur bones ever discovered. The area is now known as the Hilda mega-bonebed. The massive bodies of Centrosaurus were borne by stocky limbs, although at up to 5.5 metres (18 ft) they were not particularly large dinosaurs. Like other centrosaurines, Centrosaurus bore single large horns over their noses. These horns curved forwards or backwards depending on the specimen. Skull ornamentation was reduced as animals aged. The frill was relatively short compared to the total skull length, and could grow to over half a meter (68.8 cm) long in the oldest and largest adults.

Brachylophosaurus was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana, the Wahweap Formation of Utah and the Oldman Formation of Alberta, living about 81-76.7 million years ago. Brachylophosaurus is notable for its bony crest, which forms a horizontally flat, paddle-like plate over the top of the rear skull. Some, depending on their age, had crests that covered nearly the entire skull roof, while others had shorter, narrower crests. Some researchers suggest it was used for pushing contests, but it may not have been strong enough for this. Other notable features are a relatively small head, the unusually long lower arms and the beak of the upper jaw being wider than other hadrosaurs of that time. Apart from the above, Brachylophosaurus was a typical hadrosaur which reached an adult length of at least 9 metres (30 ft). In 2010, Gregory S. Paul estimated maximum length at 11 metres (36 ft) resulting in weight of 7 metric tons (7.7 short tons). Like other hadrosaurs, Brachylophosaurus had features like cheeks to keep fodder in the mouth and dental batteries with hundreds of stacked teeth. These teeth could be used to chew efficiently, a feature rare among reptiles, but common among some cerapodan ornithischian dinosaurs like Brachylophosaurus. A 2008 study conducted on the famous dinosaur mummy Leonardo found that Brachylophosaurus had a diet that consisted of leaves, conifers, ferns, and flowering plants like magnolias. The study also found that Brachylophosaurus was a generalist herbivore; being both a browser and a grazer, but it did more of the former rather than the latter due to the contents found in its stomach.

Pachyrhinosaurus is an extinct genus of centrosaurine ceratopsid dinosaur from the Late Cretaceous period of North America around 71 million to 67 million years ago. The first examples were discovered by Charles M. Sternberg in Alberta, Canada, in 1946, and named in 1950. Pachyrhinosaurus was both large and quadrupedal. It grew to 6 meters (20 feet) in length and weighed about 1,800 kg (almost 2 tons). Size estimates for the largest Pachyrhinosaurus species, P. canadensis indicate lengths of 6–8 meters (19.7–26.2 ft) and a weight of 3–3.6 tons (3.3–4.0 tons). An herbivore, Pachyrhinosaurus used the batteries of teeth in its jaws to slice open and consume plants. Some of its horns grew in unicorn fashion between and slightly behind the eyes, whereas others decorated the top edge of the frill. Pachyrhinosaurus also sported thickened knobs of bone; the largest of these knobs covered the top of the nose. The function of these knobs, horns, and frill is unknown, but they may have been used for species recognition, competition between males, or defense against predators. It is closely related to Styracosaurus and Centrosaurus and more distantly related to Triceratops. Like other ceratopsids, it possessed a prominent skull characterized by a narrow but massive beak and a bony frill. The Greek name Pachyrhinosaurus means “reptile with a thick nose.” Specimens of Pachyrhinosaurus are known from bone beds in southern Alberta, Can., and the North Slope of Alaska, U.S. In both locations, the bone beds contain juveniles and adults, which suggests that this dinosaur may have provided parental care by herding. Although average global temperatures were much warmer during the Cretaceous Period than they are today, Pachyrhinosaurus populations in Alaska and northern Canada did have to contend with months of winter darkness. It remains unknown whether they migrated south during the Alaskan winter.

Lambeosaurus is a genus of hadrosaurid dinosaur that lived about 75 million years ago, in the Late Cretaceous period of North America. This bipedal/quadrupedal, herbivorous dinosaur is known for its distinctive hollow cranial crest, which in the best-known species resembled a hatchet. Material relevant to the genus was first named by Lawrence Lambe in 1902. Over twenty years later, the modern name was coined in 1923 by William Parks, in honour of Lambe, based on better preserved specimens. The genus has a complicated taxonomic history, in part because small-bodied crested hadrosaurids now recognized as juveniles were once thought to belong to their own genera and species. Currently, the various skulls assigned to the type species L. lambei are interpreted as showing age differences and sexual dimorphism. Lambeosaurus was closely related to the better known Corythosaurus, which is found in slightly older rocks, as well as the less well-known genera Hypacrosaurus and Olorotitan. All had unusual crests, which are now generally assumed to have served social functions like noisemaking and recognition. Lambeosaurus, best known through L. lambei, was quite similar to Corythosaurus in everything but the form of the head adornment. Compared to Corythosaurus, the crest of Lambeosaurus was shifted forward, and the hollow nasal passages within were at the front of the crest and stacked vertically. It also can be differentiated from Corythosaurus by its lack of forking nasal processes making up part of the sides of the crest, which is the only way to tell juveniles of the two genera apart, as the crests took on their distinctive forms as the animals aged. Lambeosaurus was like other hadrosaurids, and could move on both two legs and all fours, as shown by footprints of related animals. It had a long tail stiffened by ossified tendons that prevented it from drooping. The hands had four fingers, lacking the innermost finger of the generalized five-fingered tetrapod hand, while the second, third, and fourth fingers were bunched together and bore hooves, suggesting the animal could have used the hands for support. The fifth finger was free and could be used to manipulate objects. Each foot had only the three central toes. The most distinctive feature, the crest, was different in the two well-known species. In L. lambei, it had a hatchet-like shape when the dinosaur was full-grown, and was somewhat shorter and more rounded in specimens interpreted as females. The "hatchet blade" projected in front of the eyes, and the "handle" was a solid bony rod that jutted out over the back of the skull. The "hatchet blade" had two sections: the uppermost portion was a thin bony "coxcomb" that grew out relatively late in life, when an individual neared adulthood; and the lower portion held hollow spaces that were continuations of the nasal passages. Large adult specimens of Lambeosaurus have been estimated to be around 7 m (23 ft) long. Impressions of the scales are known for several specimens; a specimen now assigned to L. lambei had a thin skin with uniform, polygonal scutes distributed in no particular order on the neck, torso, and tail. Similar scalation is known from the neck, forelimb, and foot of a specimen of L. magnicristatus.