Hoyal Cuthill, Jennifer F. Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom.
- Body plan modeling
- Links to Primary Literature
- Additional Readings
Enigmatic fossil macroorganisms, assigned to the taxon Rangeomorpha, that possessed a characteristic frond. To Charles Darwin, writing in 1859, and even to paleontologists in the early twentieth century, the evolutionary origins of macroorganisms (organisms large enough to be seen with the naked eye) remained a mystery. Rocks of Cambrian age, laid down 541 to 485 million years ago (MYA), were known to preserve fossils of recognizable marine animals (such as worms, arthropods, and cnidarians). However, no fossils of animals themselves, or their close relatives, were known from the Precambrian Era (4600–541 MYA), although tantalizing trace fossils of possible burrows and trails had been found. See also: Cambrian; Fossil; Geologic time scale; Paleontology; Phylogeny; Precambrian; Trace fossils
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information