19 Şubat 2013 Salı

Maine State Fossil

Maine State Fossil

Pertica Plant (common name)
Pertica quadrifaria 
(scientific name)
STATUS
Official 
DESCRIPTION
Pertica quadrifaria is an extinct species of fern-like plant that lived approximately 390 million years ago, during the Devonian period of the Paleozoic era. It was among the first terrestrial trees. Pertica quadrifaria is a trimerophyte, a Devonian plant with either one or two main axes. Trimerophytes are one of the four major groups of early and middle Devonian plants. They are believed to have been the most robust plants growing at this time. Pertica quadrifariafossils are valuable to paleontology because the plants were early ancestors to modern vascular land trees.
STATE SYMBOL
Fossils of the Pertica plant were first discovered in the state of Maine. Well-preserved Pertica quadrifaria fossils are found at only three other locations in the world outside of Maine. In 1985, Pertica quadrifaria was designated the official state fossil of Maine.
NAME ORIGIN
Pertica is a Latin word meaning a "long pole or rod." The scientific name Pertica quadrifaria was assigned to this plant in 1972. An ancient Roman unit of measuring length was called a pertica. It is equivalent to 10 feet or 3 meters.
BIOLOGY/ANATOMY
Thought to be the largest land plant of its time, Pertica quadrifariagrew to heights of approximately six to nine feet (2 to 3 m). This was a simple, fern-like plant without leaves or roots. Most of the plant was made of photosynthetic stems branching from a main trunk. Some branches were fertile and others were sterile. The fertile branches ended in spore cases, and the other branches had forked tips, which may have led to the evolution of leaves.
This plant grew in saltwater or brackish marshes near active volcanoes. Ashfall quickly buried fallen plants before decay could take place. The trees were eventually preserved as fossils. Millions of years later, these fossils were exposed by erosion.
EVOLUTION/EXTINCTION
The Devonian period was possibly the most important in the evolution of trees. Vascular systems, root systems, shrubs, and wood all made their first appearance in the Devonian. Pertica quadrifaria represents significant steps in the evolution of leaves and vascular land plants. Numerous modern species, including the pine tree, are descendants of this unique prehistoric plant.
MODERN DISCOVERY
Fossils of this rare plant were first discovered in 1968 in the rocks of the Trout Valley Formation in Baxter State Park, near Mt. Katahdin, Maine. 

Click to enlarge an image
State Prehistoric Creature
Pertica, an Early Devonian Plant

CLASSIFICATION
Kingdom:Plantae
Division:Trimerophytophyta
Class:(incertae sedis)
Genus:Pertica
Species:P. Quadrifaria
Author: World Trade Press


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