Pikaia gracilens is an extinct, primitive chordate marine animal known from the Middle Cambrian Burgess Shale of British Columbia.

皮卡虫（属名： Pikaia ，得名自发现地一带常出没的鼠兔 Pika），又名皮凯亚虫或皮克鱼，是一种寒武纪的原始脊索动物，其化石在加拿大 不列颠哥伦比亚的伯吉斯页岩发现。

Pikaia – from the pika, a small alpine mammal and cousin of the rabbits. Pikas live in the Rocky Mountains, including near the Burgess Shale. gracilens – from the Latin gracilens, “thin, …

2019年4月8日 · The slender, lancelet-like Pikaia is one of three early fishlike creatures found preserved from the Cambrian period in the geologic record.

A good possibility is Pikaia, a fossil discovered in the Burgess Shale (Middle Cambrian, about 530 million years old). Pikaia has myotomes and what looks like a notochord, indicating that it is a …

2024年3月16日 · Is Pikaia a fish? Although Pikaia is a chordate, the precursor to all vertebrates, Pikaia Gracilens itself is not a fish. While it shares some characteristics with modern fish, such …

Pikaia is an extinct marine organism that lived during the Early Cambrian Period – about 530 million years ago. It was first discovered and named in 1911 by Charles Walcott. He gave this …

2008年2月17日 · Pikaia (An Early Fish) By Carl Zimmer. February 17, 2008 “here is a photograph of the one my boyfriend offered me three years ago. Although I don’t work directly on the …

Pikaia was probably a chordate — the same group that includes fish, dinosaurs, and humans! A fossil Pikaia has a visible notochord and myotomes . Photo by Chip Clark, Museum of Natural …

Conway Morris and Caron (2012) have recently published an account of virtually all the available information on Pikaia gracilens, a well-known Cambrian fossil and supposed basal chordate, …