{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

The Seed Ferns - The earliest terrestrial vertebrate...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
The Seed Ferns The seed ferns, fancy name pteridosperms (literally fern-seed), appeared during the late Devonian. One of the more important groups of seed ferns was the lyginopterids, small vine-like plants that probably grew on other plants. This group produced seeds in a cupule-like structure. Animals Perhaps the earliest animals ashore were the invertebrates, most likely groups of arthropods. The oldest known terrestrial arthropod is a trigonotarbid from the Silurian. Trigonotarbids superficially looked like spiders. The major groups of terrestrial arthropods were present during the Devonian: chelicerates including mites, spiders, and arachnids; and made the transition to land life, and uniramians including flightless insects, centipedes and millipedes.
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: The earliest terrestrial vertebrate fossils are from the late Devonian. These "stem tetrapods" as they are known, were essentially fish out of water. The late Devonian lungfish had two groups, the Dipnoi (which includes the living African, Auistralian, and South American lungfishes) and the Crossopterygii, whose sole living member is the coelacanth Latimeria . Comparison of the skull, forelimb, and tooth structure of Devonian crosspterygians such as Eusthenopteron with similar areas in a more specialized tetrapod such as Ichthyostega supports descent of amphibians from Devonian crossopterygians. However, some molecular studies point to descent of the amphibians from the lungfish, the Dipnoi....
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern