Commonly known as the simple spine lizard, the Haplocanthosaurus was a sauropod dinosaur that was found in the Kimmeridgian stage of the Late Jurassic period which spanned from 155-152 million years ago. There are two known species, Haplocanthosaurus delfsi and Haplocanthosaurus priscus, that belonged to the genus. Specimens of both the species were discovered by Edwin Delfs, a college student of Colorado, the United States in the lowest layer of the Morrison Formation.
The type species was firstly named Haplocanthus priscus by John Bell Hatcher, an American paleontologist, but since Haplocanthus was already used for acanthodian fish, a new name Haplocanthosaurus priscus was given to the species.
The dinosaur is regarded as one of the smallest sauropods. The average length of sauropods is estimated to be around over 66 ft (20 m), while the Haplocanthosaurus was around 49 ft (15 m) long and its weight is said to be around 14 tons (12791 kg). The dinosaur is known for its vertebrae as it possessed a single dorsal neural spine, while a majority of diplodocus sauropods had double-pierced V-shaped dorsal neural spines. The neck vertebrae had a tall dorsal neural spine, high neural arches, while the thigh bones were quite longer than the shin bones.
Out of the four specimens of these dinosaurs, only the Haplocanthosaurus delfsi is completely mounted, while a partial skeleton is kept in the Cleveland Museum of Natural History with a replica skull as the original skull has not been discovered yet.
Generally, sauropods inhabited freshwater ponds, lakes, rivers, but these dinosaurs must have lived in dense forests, grasslands, rocky mountains. They were gregarious and used to live in groups.
Let's read more fun facts about the Haplocanthosaurus, and if you find this article interesting, don't forget to check out exciting facts about different dinosaurs like Blikanasaurus and Thotobolosaurus.
The pronunciation of the dinosaur's name seems to be a bit difficult but we are here to make it a little easier for kids. We are going to tell you a simple trick that can be applied to the pronunciation of all the names, be it dinosaurs, animals, places, and many other things. You just have to break the whole term into several syllables like 'hap-loe-kan-foe-sore-us' to make it less complicated.
The dinosaur belonged to the class of Reptilia, the clade of Dinosauria and Sauropoda, the family of Haplocanthosauridae, and the Haplocanthosaurus genus. Haplocanthosaurus delfsi and Haplocanthosaurus priscus are two known species of the genus. It is also said that the dinosaur was quite primitive than neosauropods, and macronarians.
The Haplocanthosaurus dinosaur belonged to the Late Jurassic period that spanned from 163-145 million years ago (mya). During this period, the dinosaur must have lived in different parts of the North American continent.
These sauropods must have become Extinct during the Kimmeridgian stage of the Late Jurassic period, somewhere between 155- 152 million years ago (mya). The reason for extinction is not clear as of now, but dinosaurs became Extinct due to several reasons such as climate change, volcanic eruption, asteroid impact, drought, and many more. Competition among dinosaurs can also be regarded as one of the major causes of extinction.
The discovery of the first specimen took place in the lowest layer of the Morrison Formation, Colorado, a US state. Another specimen, known as 'Big Monty' was discovered in Montana. It can be said that the dinosaur must have lived in countries such as the United States, Canada, Mexico, and many more.
Generally, sauropods inhabited freshwater ponds, lakes, rivers, but these dinosaurs must have lived in dense forests, grassland, rocky mountains. They would have nested in the vicinity of lakes, rivers, and ponds.
All species of the Haplocanthosaurus genus lived in groups. We can conclude that they were gregarious by knowing about their communal nesting habits. Young ones formed separate herds, while adults must have taken care of young ones after birth. Also, they must have formed pairs during the breeding season.
The exact life span of these primitive dinosaurs is being evaluated by paleontologists. Unlike most Sauropoda species, the species must have lived quite a bit less. Studies of fossils revealed that a few Sauropoda species may have lived for around 100 years.
Like other members of the Dinosauria clade, the primitive dinosaurs reproduced by laying eggs. Their mating patterns were very much similar to modern-day reptiles and birds. Like modern-day animals, these creatures used to perform courtship displays to attract potential partners and it is also scientifically proven that males used to fight over females.
The incubation period was likely to have been between 65-85 days, while the litter size is not known. Recovered fossils suggest that the eggs of sauropods were not bigger than a modern adult goose egg and they weighed less than 11 lb (5 kg) after hatching. Studies also reveal that the young sauropods were most likely precocial which means they were quite active from their birth.
The Haplocanthosaurus was regarded as one of the smallest sauropods found at the Morisson Formation. The dinosaur was quite shorter and stockier, unlike most dinosaurs of its clade. It had a short neck and must have eaten plants low to the ground. In other words, we can say the dinosaur was a huge spined lizard. Also, the dinosaur should not be confused with Acrocanthosaurus, a predatory dinosaur that was mainly found in North America.
The exact number of bones is not known as of now, but the primitive dinosaur is known for its vertebrae as it possessed a single dorsal neural spine, while a majority of diplodocus sauropods had double-pierced V-shaped dorsal neural spines. The neck vertebrae had a tall dorsal neural spine, high neural arches, while the thigh bones were quite longer than the shin bones. The skeleton is kept in the Cleveland Museum of Natural History, though with a replica skull as the original skull has not been discovered yet.
Both the species of the Haplocanthosaurus genus communicated in the same way as other dinosaurs. They used to communicate vocally and some researchers believed that they used to roar, but studies state it's not actually true. Like modern-day animals, they must have performed courtship displays during the breeding season to attract potential partners.
The average length of sauropods is estimated to be around over 66 ft (20 m), while the Haplocanthosaurus was around 49 ft (15 m) long and its weight is said to be around 14 tons (12791 kg). The specimen seemed to be quite a bit bigger than Montanoceratops and Aetonyx.
The thigh bones were substantially longer than the shin bones which suggests it was a very slow-moving dinosaur. However, sauropods had a top speed of around 5 mph (8 kph).
Sauropods were known for their huge bodies, the average weight of these primitive dinosaurs is said to be around 14 tons (12791 kg).
No specific names have been given to male and female dinosaurs; people generally call them Haplocanthosaurus.
Like modern reptiles, the babies of these dinosaurs are called hatchlings. Recovered fossils suggest that the eggs of sauropods were not bigger than a modern adult goose egg.
Generally, sauropods were herbivores and they must have fed on plants and leaves. Since these dinosaurs were small, they must have eaten plants low to the ground, unlike big sauropods. The creature had no sharp teeth and didn't use to bite each other.
The dinosaur was gregarious and often lived in pairs. Dinosaurs, in general, were not aggressive and didn't get violent for no reason. However, while dealing with intruders, they must have turn territorial and aggressive.
Titanosauriformes were the last surviving group of long-necked sauropods.
The genus name translates to English as a simple spined lizard as the dinosaur was quite primitive and possessed and an unspecialized spinal cord.
As of now, four specimens of these dinosaurs are found. While around seven specimens have been assigned to them, it has not been proved yet whether they belonged to the Haplocanthosaurus genus or not. Out of the four specimens of these dinosaurs, only the Haplocanthosaurus delfsi is completely mounted, while a partial skeleton is kept in the Cleveland Museum of Natural History with a replica skull as the original skull has not been discovered yet.
Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! Learn more about some other creatures from our Amazonsaurus facts, or Argyrosaurus facts for kids.
You can even occupy yourself at home by coloring in one of our free printable Haplocanthosaurus coloring pages.
Main image by FunkMonk (Michael B. H.).