In 1946, an Australian mining geologist named Reginald C. Sprigg was exploring a range of mountains north of the city of Adelaide, Australia, known as the Ediacara Hills. Serendipitously, he found fossilized imprints of what were...
The Cenozoic is the most recent of the three major subdivisions of animal history. The other two are the Paleozoic and Mesozoic. The Cenozoic spans only about 65 million years, from the end of the Cretaceous and the extinction of non-avian...
Cnidarians are incredibly diverse in form, as evidenced by colonial siphonophores, massive medusae and corals, feathery hydroids, and box jellies with complex eyes. Yet, these diverse animals are all armed with stinging cells called nematocysts. Cnidarians are united based on the presumption that...
The Rhynie Chert in Scotland is a Devonian age deposit containing fossils of both Zosterophyllophytes and Trimerophytes, the two major lines of vascular plants. This indicates that prior to the start of the Devonian, the first major radiations of the plants had already happened. The oldest known...
Dinosaurs, one of the most successful groups of animals (in terms of longevity) that have ever lived, evolved into many diverse sizes and shapes, with many equally diverse modes of living. The term "Dinosauria" was invented by Sir Richard Owen in 1842 to describe these "fearfully great reptiles,"...
These exhibits trace evolutionary thought as it has developed over time, pausing to ponder the contributions of scientists and thinkers including Aristotle, Darwin, Wallace, and many others. Explore the theory of evolution. Learn about the...
The Mesozoic is divided into three time periods: the Triassic (245-208 Million Years Ago), the Jurassic (208-146 Million Years Ago), and the Cretaceous (146-65 Million Years Ago). Mesozoic means "middle animals", and is the time during which the world fauna changed drastically from that which had...
Poriferans are commonly referred to as sponges. An early branching event in the history of animals separated the sponges from other metazoans. As one would expect based on their phylogenetic position, fossil sponges are among the oldest...
The Silurian (443 to 417 million years ago) was a time when the Earth underwent considerable changes that had important repercussions for the environment and life within it. The Silurian witnessed a relative stabilization of the earth's general climate, ending the previous pattern of erratic...
There are more than 500 species in the Oomycota -- these include the so-called water molds and downy mildews. They are filamentous protists which must absorb their food from the surrounding water or soil, or may invade the body of another...