Parachlorosaurus, also known as paracharonosaurus (zhì), is a genus of dinosaurs in the family Duckbillaceae, a herbivorous dinosaur that lived in North America during the Late Cretaceous Period, about 76.5 million to 73 million years ago.
A small number of good specimens are known, and the fossils were found in alberta, Canada, and New Mexico and Utah in the United States.
Parachlorosaurus is famous for its large, slender crown on its skull, which curves toward the back of its head.
Genus name: Parasaurolophus, meaning "lizard with almost a crown".
Realm: Animal kingdom Animalia
Phylum: Phylum Chordata
Order: Sauropsida
Order: Ornithischia
Family: Hadrosauridae
Genus: Parachlorosaurus Parasaurolophus
There are currently three recognized species:
The model species is Walker's P. walkeri
Trumpeter P. Tubicen
Short-crested parachlorosaurus P. cyrtocristatus
A reference to the proportions of Walker's paracuss with humans, lions, giraffes, and African elephants
The type marker of Walker's parachlorosaurus itself is 10–12 m long, and the skull and crown are 1.6 m long.
The skulls and crowns of the trumpeter paraceaurus model specimens are more than 2 meters, and it is inferred that they were larger than those of Walker's paracuss.
The only forelimbs found so far suggest that they were shorter than those of other platypus dinosaurs and had short, wide scapula. The type specimen of Walker's parachlorosaurus has a femur that is 103 cm long and has a stout femur.
A model specimen model of Walker's paracuss
Parachlorosaurus was a bipedal dinosaur , but could convert to four-legged walking. Paraceaurus may use a quadruped approach in search of food and a bipedal approach when running.
A female paracyclic dragon that is being attacked by a snake-haired female dragon
The neural spines on the spine of Parachlorosaurus are tall, a feature that increases the height of the back beyond the height of the hips. Skin marks have been found in Walker's Paracus, showing nodular scales on the skin.
The most famous feature of the paraceaurus is the crown ornament on the top of the head, which consists of a premaxilla and nasal bone that extends from the back of the head.
The crown is hollow, with a tube inside that runs from the nostrils to the tail end of the crown and then around the back of the head to the inside of the skull. The tubes of walker's parachlorosaurus are the simplest, while the tubes of the trumpeter paracelids are the most complex, some of which are not passable, while others are crossed and separated.
The crowns of Walker's parachlorosaurus and trumpeter paracuss are longer and slightly curved, while the crown of the short-crowned sub-ctenophorus is shorter.
It is generally believed that the crown ornaments of the paracephalus change with age and are sexually alien features of adult individuals.
There are many hypotheses about the function of the crown ornament, but many are inconsistible. Crown ornaments are now thought to have several functions: visual displays that distinguish species from sex, speakers for communication, and body temperature regulation. It is uncertain which function was most important in the evolution of the crown and the internal nasal canal.
Social features:
Social and physiological functions are now the most supported theories, especially visual identifiers and speaker communicators. As a large object , the crown of the paracephalus was used as a clear visual identifier to distinguish it from other animals of its time.
The scleral rings and large orbits show that they have precise vision and daytime habits, and the crown decoration is a visual identifier that will be very important for this group of animals. If the crown of the paracephalus had skin folds behind the neck, according to this theory, these skin folds would be gorgeous and eye-catching. The shape and size of the skull of a parachlorupe can be used to identify species and sex differences.
Sound function:
Studies have shown that Walker's paracussosaurus is capable of producing audio from 48 to 240 hertz, while short-crowned paracuss can produce audio from 75 to 375 hertz.
Computer simulations showed that the internal pipes of the trumpeter paracuss were more complex than those of the Walker paracuss, allowing the computer to reconstruct the possible sounds emitted by the crown. The main pipes can produce about 30 Hz of audio, but the complex sinus structure controls the peaks and lows of the sound.
Cooling function:
The large surfaces of the crown ornaments with blood vessels show that they have a thermoregulatory function. P.E. Wheeler first proposed in 1978 that these crowns were used to cool the brain temperature.
Functional assumptions that are denied
Early belief that paraceaurus was an animal that depended on water continued into the 1960s.
Thus Alfred Romer hypothesized that the crowns were used as submersible breathing apparatus;
Martin Wilface used these tubular crowns as active breathing and food collectors;
Charles Sternberg believed that they prevented water from entering the lungs;
Ned Colbert believes they are used as air storage rooms to spend more time in the water.
Some hypotheses are more physiological.
William Parks believed that there were ligaments or muscle attachments between the crown and the spine, which could assist in supporting the head and assisting in head movements;
Othenio Abel hypothesized that the crowns were used as weapons in intraspecies fights;
Angela Milner believes they are leaf-like converters, resembling the crown of a crane ostrich;
John Ostrom believed that the crown had an extended area of the olfactory epithelium that assisted their sense of smell, rather than having a defensive function;
Creationist Duane Guisch proposed that these crown storers chemical glands, when encountered by enemies, they could spew chemical liquids, similar to today's farting beetles;
Some assume that the crown is a storage organ, storing salt glands.
Most of the above assumptions are rejected, for example:
There is no hole in the rear of the crown to snorkel. There are no muscle marks on the proboscis, and the paracus already has a beaked mouth, is the proboscis still needed? If used as an air lock, these crowns do not prevent water from entering. If the crown is used as an air storage room, because of the large size of the paraceaurus, the efficiency provided is not great.
Studies have shown that the olfactory nerves and sensory organs are not located in the nasal part of the crown, so these crowns should not have olfactory function.
We can actually use our imaginations
Anything that could possibly have...
Parachlorosaurus was a large, herbivorous dinosaur that could have walked bipedal or quadruped, with complex skulls allowing for chew-like grinding motions. The teeth of Parachlorosaurus were constantly growing and replacing, they had hundreds of teeth, and only a small number of teeth were used at a time.
It uses its beak-like mouth to cut plants and feed them into the cheeks on either side of the mouth. Their feeding range is about 4 meters above the ground.
The discovery and naming of the paraceaurus
Walker's Paracuss
P. walkeri
Walker's Vice Ctenophorus Imaginary
The type specimen of Parachloros ( number ROM708 ) contains a skull with part of the skeleton , missing the hind limbs below the knee and most of the tail.
The specimen was discovered in 1920 by a field team from the University of Toronto near the Sand River on the Red Deer River in Alberta, Canada. The specimen was found in the dinosaur park formation and dates to the Campan Steps of the Upper Cretaceous.
The fossil was named by William Parks as P. Walker's Paracus. walkeri), named after Sir Byron Edmund Walker, Chairman of the Board of Trustees of the Royal Ontario Museum.
Trumpeter Vice Ctenophora
P. tubicen
Trumpeter Deputy Ctenophora Imaginary
In 1921, Charles Hazelius Sternberg discovered a partial skull in the Kitland Formation in San Juan County, New Mexico, which was younger than the Dinosaur Park Formation.
The fossils were sent to Uppsala, Sweden, and carl Wiman described them in 1931 as a second species, the trumpeter P. tubicen）。 The species name tubicen is derived from the Latin word for trumpeter.
The second near-intact skull (NMMNH P-25100) was discovered in New Mexico in 1995.
Short-crowned parachlorosaurus
P. cyrtocristatus
Short-crowned para-ctenophora imaginary diagram
The specimen contains a partial skull with a round, short crown, and most of the skeleton behind the skull, except for the feet, neck, and part of the tail. The specimen is currently located at the Field Museum of Natural History.
The species name cyrtocristatus is cyrtocristatus in Latin for "shortened crown ornament".
Fossils of Apatosaurus brachycephalus were found in New Mexico and Utah and contain three possible specimens. The short-crowned paraceaurus is the smallest paracribacta , with a shorter , rounder crown.
Recently, Thomas Williamson hypothesized that they were juvenile or female individuals of the trumpeter Paracus, based on the small size and crown shape of the short-crowned paraceastosaurus.
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