Geologist Bob Brown and his wife Nancy recently conducted an explorative trip around Bingara and surrounding district. Having been successful in co-founding a geoscience society in Armidale - GSUNE, one of their aims was to involve people interested in geoscience in field activities, so an invitation was extended to Gwydir Shire residents to join the expedition [Read more...]
The weekend trip with a contingent of students and locals was immensely successful with a rare find stumbled upon only 100mtrs from the entry gate to Eungai HS. The geology team identified a Leptophloeum with a well preserved trilobite attached. Unfortunately it was found on the floor of the pit and is too delicate to be removed.
According to a UNE (University of New England) Paleontologist this is the most northern example of a Late Devonian trilobite ever found, dating back about 350 million years.
Leptophloeum is the name given to a giant Lycopod or scale tree from the Devonian of Australia. It is related to Lepidodendron which formed an important part of the coal swamps of the late Carboniferous which grew to heights in excess of 40 meters.
This specimen is from a rarely-seen location, and is excellently preserved. The leaf scars make it easy to see how the name scale tree was derived. The distinctive near square shape of these scars shows it to be from a mature part of the bark.
While the later Lepidodendron bore larger leaves, those of the more ancient Leptophloeum were more inconspicuous.
Trilobites were among the early arthropods, a phylum of hard-shelled creatures with multiple body segments and jointed legs (although the legs, antennae and other finer structures of trilobites only rarely are preserved). They constitute an extinct class of arthropods.
The trilobite is one of the first creatures to climb from the primordial ooze. It survived from the Cambrian period 350 million years ago to the Permian mass extinction about 245 million years ago. The demise of most of the earth's creatures at this mother of all extinctions, led to the Age of the Dinosaurs. At this time the earth's continents were all together in a supercontinent called Pangea.
The last of the Trilobites exited in the Permian period around 251 million years ago.
The Permian period lasted from around 290 to about 248 million years ago and was the last period of the Paleozoic Era. The major difference between the Paleozoic and the Mesozoic was one of the largest groups of extinctions in recorded history. This affected many groups of animals, but it mostly affected marine life.
Some of the groups of sea life survived this mass extinction but they never recovered their large populations again. This cleared the way for new species of sea life. On land a smaller extinction was going on. This extinction led to what is known as "The Age of the Dinosaurs". The plants in this age also switched over to gymnosperms instead of being Cycads.
In the beginning of the Permian the plates of the earth brought the super-continent of Pangaea together. Most of the continents came together in Pangaea; the super-continent took up much of the area between the southern and northern poles. The rest of the Earth was covered by a single ocean known as Panthalassa with a smaller ocean to the east called Tethys.