Aysheaia
Encyclopedia
Aysheaia was a genus of soft-bodied
, caterpillar
-shaped organisms average body length of 1–6 cm. The genus name commemorates a mountain peak named "Ayesha" due north of the Wapta Glacier
. This peak was originally named Aysha in the 1904 maps of the region, and was re-named Ayesha after the heroine of Rider Haggard's 1887 novel She. They are known from fossil
s found in the middle Cambrian
Burgess shale
of British Columbia
, and from the Wheeler Formation in Utah
. Similar forms are known from the lower Cambrian Maotianshan shales of China
. Aysheaia has ten body segments, each of which has a pair of spiked, annulated legs. The animal is segmented, and looks somewhat like a bloated caterpillar with a few spines added on — including six finger-like projections around the mouth and two grasping legs on the "head." Based on its association with sponge
remains, it is believed that Aysheaia was a sponge
grazer and may have protected itself from predators by seeking refuge within sponge colonies. Aysheaia probably used its claws to cling to the sponge.
Unlike many early Cambrian forms whose relationships are obscure and puzzling, Aysheaia is remarkably similar to a modern phylum, the Onychophora. Other than the 20 specimens from the Greater Phyllopod bed
, where they comprise 2% of the community, only 19 specimens of A. pedunculata are known. A. prolata is the species from the Wheeler Formation.
Soft-bodied organisms
The term "soft-bodied organism" is used to describe animals without skeleton, roughly corresponding to the group Vermes as proposed by Carl von Linné. All animals have muscles, but since muscles can only pull, never push, a number of animals have developed hard parts that the muscles can pull on,...
, caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
-shaped organisms average body length of 1–6 cm. The genus name commemorates a mountain peak named "Ayesha" due north of the Wapta Glacier
Wapta Glacier
The Wapta ice fields are a series of glaciers popular with climbers on the border of Alberta and British Columbia in Yoho National Park in the Canadian Rockies. The Burgess shale animal Waptia takes its name from these features. Their meltwater feeds the nearby Wapta falls....
. This peak was originally named Aysha in the 1904 maps of the region, and was re-named Ayesha after the heroine of Rider Haggard's 1887 novel She. They are known from fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s found in the middle Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
Burgess shale
Burgess Shale
The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...
of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, and from the Wheeler Formation in Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
. Similar forms are known from the lower Cambrian Maotianshan shales of China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. Aysheaia has ten body segments, each of which has a pair of spiked, annulated legs. The animal is segmented, and looks somewhat like a bloated caterpillar with a few spines added on — including six finger-like projections around the mouth and two grasping legs on the "head." Based on its association with sponge
Sea sponge
Sponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
remains, it is believed that Aysheaia was a sponge
Sea sponge
Sponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
grazer and may have protected itself from predators by seeking refuge within sponge colonies. Aysheaia probably used its claws to cling to the sponge.
Unlike many early Cambrian forms whose relationships are obscure and puzzling, Aysheaia is remarkably similar to a modern phylum, the Onychophora. Other than the 20 specimens from the Greater Phyllopod bed
Phyllopod bed
The Phyllopod bed, designated by USNM locality number 35k, is the most famous fossil-bearing member of the Burgess shale fossil lagerstatte. It was quarried by Charles Walcott from 1911–1917, and was the source of 95% of the fossils he collected during this time;tens of thousands of...
, where they comprise 2% of the community, only 19 specimens of A. pedunculata are known. A. prolata is the species from the Wheeler Formation.