The terrestrial inhabitants of the Early Jurassic to the Late Cretaceous periods of the Mesozoic Era (nearly 70-65 million years ago), the thyreophorans (a Greek word meaning 'shield bearers') or colloquially called 'armored dinosaurs', comprised a group of ornithischians.
Two major groups among them were the ankylosaurs and stegosaurs (particularly found in the Late Jurassic-Late Cretaceous period). They were first formally named and described by Nopcsa in 1915 while Paul Sereno was the first to identify their clade in 1998.
Fossil remains of these quadrupedal creatures were procured from several locations across the globe namely, Western North America, Eastern Africa, Western Europe, Eastern Asia, and Australia.
They were herbivores by nature and dwelled in open fields, forests, and grasslands with heavy vegetation.
The primary characteristic features that they displayed were a fully armored form accompanied by rows of spikes and plates and a tail club.
Scutellosaurus was the smallest armored dinosaur of this group. Overall, the measurements of this clade are 13.12 ft (4 m) and 4.92 ft (1.5 m) in length and height, respectively, with a small skull and an elephantine form with hind legs that were much longer than the front legs.
Accurate information regarding life expectancy, reproductive behavior, weight, and other aspects could not be furnished in this article due to a dearth of substantial data.
Keep reading to discover more interesting facts about the Thyreophorans! If you like this article, do not forget to check out Rhabdodon and Morelladon to discover and learn various lesser-known facts about them.
Thyreophora Interesting Facts
How do you pronounce 'Thyreophora'?
The word 'Thyreophora' is a cluster of five syllables which when pronounced sounds like 'thigh-ray-o-foe-rha'. Nopcsa was the first to render the thyreophorans their formal identification in 1915.
What type of dinosaur was a Thyreophora?
The thyreophorans belong to the animal kingdom of class Reptilia and order Ornithischian. More than one genus exists under the Thyreophora group. An extinct group of heavily armored, four-legged ornithischian dinosaurs is known as thyreophorans. This group of dinosaurs consists of various subgroups and are closely related to two major groups, Stegosaurs, and Ankylosaurs.
In which geological period did the Thyreophora roam the earth?
The primitive thyreophorans can be dated back to approximately 66-70 million years ago, from the Early Jurassic till the Late Cretaceous period of the Mesozoic Era. Ankylosaurs are estimated to live from the Early to Late Jurassic, while the Stegosaurs from Late Jurassic to the Late Cretaceous period.
When did the Thyreophora become extinct?
The exact time frame within which the dinosaur species dissolved into extinction cannot be mentioned but researchers believe that the Late Cretaceous period underwent several natural disasters, especially volcanic eruptions and global warming, which served as major causes for their extinction.
Where did a Thyreophora live?
Thyreophorans was a cluster of several ornithischians whose fossils have been found from all across the globe. Numerous excavations carried out in parts of Western North America, Eastern Africa, Western Europe, Eastern Asia, and Australia have led to the discovery of their remains.
What was a Thyreophora's habitat?
Not much is known about the type of habitat that the thyreophorans preferred to live in several million years ago. However, considering that they were herbivores by nature, it can be assumed that these terrestrial ornithischian dinosaurs inhabited open fields and grasslands with heavy vegetation.
Who did a Thyreophora live with?
Generally, ornithopods were found living in herds or groups but such was not the case for thyreophorans. They were solitary creatures. Researchers have made this claim based on the fact that no fossil remains of groups of these dinosaurs were found together at a particular excavation site.
How long did a Thyreophora live?
The exact lifespan of thyreophorans lacks detailed research. However, the average life expectancy of dinosaurs, in general, is estimated to be 70-80 years. So, the same can be concluded for this species as well.
How did they reproduce?
Just like all other dinosaurs, reproduction among ornithischians, particularly thyreophorans, was oviparous and they reproduced by laying eggs. According to relevant findings, females laid one to three eggs inside nests and incubated them for around six months.
Subsequently, baby dinosaurs hatched out of these eggs and needed no parental care after birth. Detailed information regarding breeding seasons, courtship rituals, and other reproductive behavior is not known yet.
Thyreophora Fun Facts
What did a Thyreophora look like?
Very little, perhaps only the minor forms of the body of ornithopods, is known since the Early Jurassic period failed to store most of the fossil remains. However, the recoveries have shed some light on the forms of these dinosaurs.
The two major groups of Thyreophora dinosaurs -- stegosaurs and ankylosaurs exhibit more or less the same features barring some exceptions. These bird-hipped dinosaurs have heavy body armor accompanied by parallel rows of plates or spikes along the body.
The ankylosaurus is further divided into two groups, ankylosaurids, and nodosaurids. The feature that distinguishes the ankylosaurus from the stegosaurus is the tail. All the irregular bones of the spinal column had merged together to compose the tail club.
The entire body from head to tail is covered with heavy armor and two rows of plates and spikes along the body line. Ankylosaurus also had two horn-like spikes on either side of its skull. Scutellosaurus, a contemporary of an ankylosaurus, had spikes instead of plates.
Stegosaurus, on the other hand, is also further divided into two groups, Stegosauridae and Huayangosauridae. Stegosaurus possessed a small skull with leaf-shaped teeth. The entire body of the stegosaurus was also covered with body armor accompanied by rows of plates and spikes.
The bony plates are formed by merging external bones. The evolved species have a more elaborate armor structure with more plates and spikes.
In addition, both of them had four legs (quadrupedal), and broad hands and feet, also covered in spikes. Both groups had strong legs with the hind legs being longer than the front legs. They had broad graviportal feet that were not adapted for running.
How many bones did a Thyreophora have?
Fossil remains from the Early Jurassic period are scarce as it failed to store most of them. Consequently, with several missing parts of the forms, it is impossible to estimate the exact number of bones that these armored dinosaurs possessed.
How did they communicate?
It is believed that the primary mode of communication in dinosaurs involved vocal and visual cues. The vocalizations produced by them sounded like a horn. Unfortunately, the communication pattern unique to the ornithischians is yet to be uncovered.
How big was a Thyreophora?
Both ankylosaurs and stegosaurs were identical in size and shape. Their form was the shape of a trunk that was 13.12 ft (4 m) in length and 4.92 ft (1.5 m) in height. They were three times smaller than the famous T. rex that was 40 ft (12.19 m) in length and 12 ft (3.65 m) in height!
How fast could a Thyreophora move?
Generally, ornithischians had broad but strong feet that were not adapted for running. Hence, it can be safely assumed that they were slow, low-level browsers, and exceptionally relaxed in their movement.
How much did a Thyreophora weigh?
There is no unifying figure to provide an estimate regarding the average weight of these primitive bird-hipped creatures that lived several million years ago (Early Jurassic-Late Cretaceous period). Nonetheless, paleontologists have been able to suggest that stegosaurus most likely weighed between 6800-15400 lb (3084-6985 kg).
In spite of boasting a weight nearly equal to a small truck, its physical build lacked the enormity of the members of the genus Argentinosaurus that weighed nearly 154000 lb (69853 kg)!
What were the male and female names of the species?
The male and female counterparts of this armored dinosaur species have no separate names assigned to them. They can simply be referred to as male and/or female thyreophoran.
What would you call a baby Thyreophora?
Since babies of these armored dinosaurs hatched out of eggs like all other dinosaur species, they are called hatchlings.
What did they eat?
Research shows that thyreophorans, especially stegosaurus dinosaurs had leaf-shaped teeth that were well-suited for tearing and grinding leaves of trees. Hence, it can be concluded that they were herbivores by nature.
How aggressive were they?
The level of aggression that this group of armored dinosaurs showed lacks scientific detail. However, considering their leaf-shaped teeth and the fact that they were herbivores by nature, it can be partially concluded that they were not very aggressive.
However, the bony armor and the tail club were specifically used as lethal weapons to attack predators. Hence, it can be said that they showed aggression only when they felt threatened or provoked.
Did you know...
Apart from being used as weapons to scare away predators, the plates found on the body of stegosaurus and ankylosaurus were instruments of display used to identify and attract mates. Furthermore, studies show that the plates played an important role in controlling the body temperature in stegosaurs.
Different types of Thyreophora
The Thyreophora clade is a group of primitive armored ornithischians that roamed the Earth approximately 65-70 million years ago (Early Jurassic-Late Cretaceous period). Scanty fossil remains that have been procured suggest that this group consisted of several suborders, especially ankylosaurus and stegosaurus.
The ankylosaurs are further divided into ankylosaurids and nodosaurids while the stegosaurs are divided into Stegosauridae and Huayangosauridae.
What characteristics are unique to the Thyreophora?
The most unique feature of these dinosaur species is the armored body and a club tail (found in ankylosaurus only). Their bodies had rows of spikes and plates that were composed of external bones.
The later versions were more elaborate with many more spikes and plates. In addition, the size of their skull was way smaller in comparison to the size of their body.
Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! For more relatable content, check out these Hesperosaurus facts and Lurdusaurus fun facts pages.
Bachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management
Moumita DuttaBachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management
A content writer and editor with a passion for sports, Moumita has honed her skills in producing compelling match reports and stories about sporting heroes. She holds a degree in Journalism and Mass Communication from the Indian Institute of Social Welfare and Business Management, Calcutta University, alongside a postgraduate diploma in Sports Management.
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