The rocks exposed at Blue Beach contain many fossils. In fact,
there are so many fossils that it is almost impossible to put your
foot down without stepping on a record of ancient, past life. The
fossils at Blue Beach-Horton Bluff can be divided into four groups:
three groups of body fossils (plants, invertebrates, vertebrates);
and trace fossils. Trace fossils are indirect evidence of ancient
life and include such things as footprints, body drags, and
coprolites. 
Plants
Perhaps the most striking plant fossils at Blue Beach are
clubmoss trunks and roots. Today, clubmosses (lycopods) are
represented by Lycopodium, a small modern fern-like herb. But
Carboniferous lycopods grew into stately trees (lycopsids), though
with a different structure from modern trees. They were different
internally and did not have an outer bark as we know it today. The
most common plant fossil at Blue Beach is Lepidodendropsis, an
early form of a lycopsid. Lycopsids in the later Carboniferous
dominated the coal swamps', growing to heights of 40 metres.
Lycopsids had unusual trunks, the weight being supported by an
outer thick rind of bark (periderm). The trunks had very little
xylem - the vascular tissue that moves water from the roots and
forms the wood of most modern trees - and the interior consisted
mostly of spongy, weak tissues. The fossilized roots of lycopsids
are called Stigmaria. When in growth position, Stigmaria usually
had long rootlets that penetrate radially into the surrounding
rock.
Other plant fossils include Asterocalamites (an early Calamites,
related to modern-day horsetails), a fern called Adaintites, four
different types of seed ferns (plants that looked like ferns, but
reproduced by seeds instead of spores), and a seed called
Carpolithus (from a gymnosperm). Megaspore beds are also found -
megaspores can be seen by the naked eye.
Invertebrates
The invertebrates discovered at Horton Bluff-Blue Beach all stem
from the aquatic realm. Some can be observed with the naked eyes,
but most are microscopic. Invertebrate fossils include foraminfera,
ostracodes ("water fleas"), thecamoebians, polychate worms
(Spirorbis), clam shrimp, and a possible trilobite fragment. The
invertebrates have been invaluable in determining the different
palaeoenvironments preserved in the section. Tibert (1996) used
ostracodes and foraminifera to determine that the section had
periodic connections with the sea, although the dearth of marine
fossils show that open marine conditions were probably not
nearby.
Vertebrates
The vertebrate fauna at Blue Beach consists of no less than five
different types of fish and a few different types of amphibians.
The vertebrate fauna are currently being studied by a number of
palaeontologists from around the world. The vertebrate fossils at
Blue Beach are of world-wide significance because they are from a
very important period of time in the Earth's history. During the
Early Carboniferous, vertebrates were still making their transition
from water to land. Very few vertebrate fossils have been found
from this time period, and this lack or scarcity of fossils has
been referred to as "Romer's Gap", after the palaeontologist who
first noticed the gap in the fossil record.
The fossils at Blue Beach have the potential to fill this
critical gap in our knowledge base. The different types of fish
fossils found in the section include acanthodians (bony fish with
distinctive spines in front of all fins), chondrichthyians (sharks
- cartliaginous fishes), palaeoniscids (ray-finned fishes),
crossopterygians (lobe-finned fishes with large, stabbing teeth),
and dipnoans (lungfish). The amphibian record is not as well known
- largely because the fossils have not been studied in detail
before and also because the fossils tend to be fragmentary in
nature.
Trace Fossils
Trace fossils are indirect evidence of ancient life. Trace
fossils form in place and as such, give a record of an animal at a
very precise time. Trace fossils give us information that body
fossils simply cannot - they tell us about the animal's behaviour.
There are many fascinating trace fossils to be found at Horton
Bluff-Blue Beach. There are traces of fish swimming and amphibians
walking or crawling. There are many invertebrate traces (made by
worms and arthropods) that record behaviours such as walking,
resting, or feeding.
To get credit for the EarthCache please complete the following
task.
The task is
get a picture of your gps and a fossil you found to prove you where
at the site. Identify if the fossil you found is
plant/animal(invertebrates or vertebrates) or a foot print / body
drag.
You do not need to wait for confirmiation from me before posting
online. However, any logs that do not fulfill ALL requirements will
be deleted.