Wednesday, September 29, 2010

3. Conifers, Gymnosperms, and Angiosperms.

 A fossil and pseudofossil miscellany.

Bits of shale with minerals.

Cercidiphyllum obtritum (from the Katsura family)
Lake bottom debris: Pinus (Pine), Picea wing seed, Sciadopitys (from the Umbrella pine family)

Dendrites (mineral stain on shale)
Bioturbation (worm burrows)

Metasequoia occidentalis
Dawn Redwood (from the Redwood subfamily)

Stonerose has a huge list of fossils that have been found on site, numbering around 148. Most fall under the conifer, gymnosperm (Gymnosperms, meaning naked seed {their seed forms outside the reproductive organs}, were the dominant land plant in the Jurassic and Cretaceous. You know what that means: herbivorous dinosaur food! Relatives of these gymnosperms survive today in members of the conifer, cycad, and gingko families.), and angiosperm categories (Angiosperms, meaning vessel seed, {their seed forms, not surprisingly, inside the ovary} are all flowering plants). Trace and pseudofossils are also found at Stonerose. Trace fossils, including things like tracks, burrows (like the worm burrows Mom found) and coprolites (fossilized poo), are the result of an animal's activity upon their environment; they have cool names like Locomotive Traces (tracks), Dwelling Traces (excavations), and Hiding Traces (shallow excavations). Pseudofossils are naturally-occurring, though inorganic, features in rocks that are often mistaken for fossils (like the mineral dendrites Mom found). Dendrites usually form a branch pattern, which is why they're often mistaken for plant fossils. While pseudofossils are not evidence of prehistoric life, they're still awesome!

More please!
Mom and I couldn't stop thinking about the fact that we were the first people to look at these fossils...ever. That we'd opened up the rock and exposed them to the first sunlight they had seen in over 40 million years. These plants grew and greened just as the first grasses, proto-dogs, deer, and pigs began to appear. Their fossils had existed, hidden, before horses and saber-tooth cats, before Australopithecus, before the flood basalts erupted in Washington and Oregon, and before the western edge of the continent had completely formed. The shale was cold when we pried it from the hillside, damp in places when we opened the halves like books. I looked and Mom looked and we want to do it again.
P.S. I rock hammered my left hand just a tiny bit. I have a bruise, which is very noticeable to me but doesn't really show up in pictures. You'll just have to trust me on this one.

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