Anomalocaris facts for kids
Quick facts for kids Anomalocaris |
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| ROMIP 51212, a largely complete specimen of Anomalocaris canadensis. | |
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| Life restoration of Anomalocaris canadensis. | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | †Dinocaridida |
| Order: | †Radiodonta |
| Family: | †Anomalocarididae |
| Genus: | †Anomalocaris Whiteaves, 1892 |
| Species | |
(8 more unnamed species) |
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Anomalocaris means "unlike other shrimp." It was an ancient sea creature, a type of radiodont. These were early relatives of today's arthropods, like crabs and insects. Anomalocaris lived a very long time ago, during the Cambrian period.
The most famous type, A. canadensis, lived in what is now Canada. Its fossils are often found in the Burgess Shale in British Columbia. Another type, A. daleyae, has been found in Australia. Fossils have also turned up in China and the United States.
For a long time, scientists thought different parts of Anomalocaris were separate animals. Its mouth, grasping arms, and body were all found apart. But in 1985, two scientists, Harry B. Whittington and Derek Briggs, figured out they all belonged to one amazing creature.
Like other radiodonts, Anomalocaris had flaps along its body for swimming. It also had big compound eyes, like those of a fly. It had a pair of special arms at the front of its head. These arms were used to grab its food. A. canadensis could grow up to about 38 centimeters (15 inches) long. This made it one of the biggest animals in the Cambrian seas. Scientists believe it was one of the first "apex predators," meaning it was at the top of the food chain.
Contents
How was Anomalocaris Discovered?
The story of how Anomalocaris was discovered is quite interesting. Scientists first found its fossils but didn't know what they were.
- 1886-1888: The first fossils were collected by Richard G. McConnell. He was part of the Geological Survey of Canada.
- 1892: Joseph Frederick Whiteaves, a scientist, described these fossils. He thought the mouth, arms, and body were from three different animals.
- 1911: Charles Doolittle Walcott found a fossilized mouth from a similar animal. He thought it was a jellyfish and called it Peytoia.
- 1928: Another scientist, Kai Henriksen, thought the Anomalocaris arm belonged to a different creature called Tuzoia. But later, it was suggested it was part of an unknown arthropod. This turned out to be right.
- 1978: Simon Conway Morris looked at a full body fossil. It was first thought to be a sea cucumber. He realized it was the "jellyfish" Peytoia on top of a sponge.
- 1980s: Harry B. Whittington was studying a fossil from the Burgess Shale. He found two Anomalocaris "shrimp" parts attached to a large body. This body also had the "jellyfish" Peytoia as its mouth. This amazing discovery finally showed what Anomalocaris truly was!
- 2011 and 2020: Scientists found the compound eyes of Anomalocaris in Australia. This proved that Anomalocaris was indeed an arthropod. It also showed that advanced eyes developed very early in Earth's history. This happened even before animals had jointed legs or hard outer shells.
What Did Anomalocaris Look Like?
Anomalocaris was huge for its time. It could grow up to about 38 centimeters (15 inches) long. This measurement does not include its long grasping arms or tail.
It had a wide body made of 14 segments. Its body was widest in the middle and got narrower towards its tail.
Anomalocaris had a pair of very large compound eyes. These eyes were on each side of its head.
Its mouth was unusual. It was a large, disk-like shape made of 32 overlapping plates. This mouth looked a bit like a pineapple ring. It was called an oral cone.
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Oral cones of Anomalocaris (A), Peytoia (B) and Hurdia (C).
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How radiodont body flaps moved (like Anomalocaris).
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The head sclerite structure of Anomalocaris.
Anomalocaris had strong arms at the front of its head. These arms had sharp spikes on each part. It probably used them to grab its prey. It swam by moving rows of flexible flaps along its body. These flaps acted like a single fin, helping it move fast through the water. It also had a large, fan-shaped tail. This tail likely helped it push itself forward.
What Did Anomalocaris Eat?
Scientists have different ideas about what Anomalocaris ate. Some think it was a powerful hunter. They believe it could crush creatures with hard shells, like trilobites, using its mouth.
However, other scientists think its mouth and "teeth" were too soft for this. They suggest it likely ate softer things. This could include worms, tiny living things, or plankton. It might have eaten very small trilobites. It could also have eaten trilobites that had just shed their old shells. Their new shells would not have been hard yet. But most trilobites would have been too tough for Anomalocaris to eat. There is no clear fossil proof that Anomalocaris ate hard-shelled prey.
Where Did Anomalocaris Live?
Scientists believe Anomalocaris lived all over the world. Fossils have been found in many places. These include Australia, Canada, China, Greenland, and the USA. This shows that the species could live in many different types of environments.
Anomalocaris mainly lived in the ocean. During the Cambrian period, oceans covered about 85% of Earth. Today, they cover about 70%. It is thought that Anomalocaris lived in both shallow and deep waters. It could live as deep as 1,000 meters (3,300 feet). Its well-developed eyes suggest it might have preferred deeper, darker places.
See Also
In Spanish: Anomalocaris para niños
- 8564 Anomalocaris, an asteroid named after this animal.
- Radiodonta, extinct arthropod order composed of Anomalocaris and its relatives.
- Houcaris, Lenisicaris, Innovatiocaris, Guanshancaris, Echidnacaris, radiodont genera containing species originally named as Anomalocaris.
- Aegirocassis, a giant filter-feeding radiodont from Ordovician Morocco.
- Cambrian explosion, the large bio-diversification event that occurred during the Cambrian.
- Opabinia, a genus of bizarre stem-group arthropod distantly related to the radiodonts.
- Wiwaxia, a genus of possible mollusk that had copious numbers of carbonaceous scales, and lived alongside Anomalocaris.
- Paleobiota of the Burgess Shale
