Thursday, February 25, 2010

Go East - Where the fossils lie!

Happy as a piddock in a rock

A huge fossil

A sea potato (Echinocardium cordatum)

Another crinoid (from Garryvoe)

Covered in fossils

Rugosa coral

and another

Rock from Ballybrannigan

Bryzoan fossil
Brachiopod fossil

Gastropod fossil

Showing to 2 parts of the rock found in Ballybrannigan....

....reavealing a crinoid fossil
A guest post by Ken.

Date 190210

Today we decided to go East. Two beaches we visited there, one in Ballybrannigan and the other in Garryvoe.

Ballybrannigan is near Cloyne, Co. Cork and is a really beautiful strand. We found brilliant specimens of crinoids and one particular coral species. We can see the segmented strands so maybe it could be a graptolite. In one rock I found the bryzoan, a little brachiopod and possilby a gastropod.

In Garyvoe, Ballycotton Bay we found another great crinoid specimen. Also we discovered a huge boulder covered in brachiopod fossils aswell as a few horn-coral fossils (Order Rugosa). Overall the day was a boon for fossils.

In Garryvoe we noticed that a lot of the limestone rocks were riddled with holes. These were caused by piddocks (Pholas dactylus). Pinn et al. 2005 note that these bivalves bore into the substratum and suggest that, because of this cryptic lifestyle, we know very little about their biology or ecology. However we do know that early naturalists were fascinated by their luminescence and boring ability. The luminescent properties even while being eaten was noted as early as AD77 by Pliny the Elder. And the Romans were reported to have eaten them. [Pinn et al. 2005 Burrow morphology, biometry, age and growth of piddocks (Mollusca: Bivalvia: Pholadidae) on the South coast of England Marine Biology 147 pp. 943-953].

See picture above of the piddock happily nestled in the rock (he's dead btw!).
We found a lovely specimen also of a sea potato (Echinocardium cordatum), a heart-shaped sea urchin adapted for burrowing.

Anyway, another great day for the 21st Century Naturalists.


A Church Bay Day - Hello Mr. Slater

Church Bay
Surf's Up!

What a view!

A sea slater (Ligia oceanica)

Cuttlefish eggs

A fine chert specimen

A belemnite

A brachiopod

A crinoid from Church Bay

A crinoid

Song Thrush (T. philomelos)

A guest post by Ken.
Date 110210

Today we went to Chruch Bay near Crosshaven to search again for more fossils and whatever else we could find. We were pleasantly surprised. Even before we reached the beach we we greeted by a song thrush (Turdus philomelos), an early offshoot of the Turdus lineage before they diversified and spread thoughout the world and so less closely related to the thrush species such as the blackbird (T. merula).
When we got to the beach we started our search and although at first we thought we had not gathered many fossils. On later inspection on a Carrigaline kitchen table we discovered a few of our old friends the belemnites (Belemnoidea cohort), the crinoids (Crinoidea class a.k.a. sea lilies) and brachiopods.

Then later, under a rock we found a sea slater (Ligia oceanica). It was noted by Alexander that they are nocturnal animals and can be easily caught at night. "Practice is needed to catch the animals because they can move with surprising speed and agility over very rough terrain" [Alexander C. G. (1972) Locomotion in the isopod crustacean, Ligia oceanica (Linn.) Comp. Biochem. Physiol. 42, 1039-1047]. We had no such issues and just picked up the rock. Take a look at this guy's peepers. he soon went his own way with all of his seven pairs of legs.

Later, we met a guy with a dog who said his mother grew up in Church Bay. He gave us a brief history of the area and explained that a lot of it was built by the British Army. Two pools were built, one for the women and one for the men but the beach itself he said has risen a lot over the years and so these pools would not be as deep. The surrounding cliff face had worn away quite bit also and he pointed out where you could see the old concrete foundation of a diving board. He said that a lot of college students called to this beach and although at first we thought it might have been because of the fossils although it looks more likely it was the meeting of both sandstone and limestone formations that is probably of geological interest to them.
What a day!

Wednesday, February 24, 2010

Rotifers: Piquing Curiosity for 300 Years

"I saw here also an animal like a maggot which would contract itself up into a spherical figure and then stretch itself out again; the end of its tail appeared with a forceps, like that of an Ear-wig ... and they seemed to be busy with their mouths as in feeding"

Harris, 1696, Philosophical Transactions of the Royal Society

So said John Harris, writer, scholar, Rector of Winchelsea in Sussex and naturalist in the first recorded encounter with these animals in 1696. The Rotifer specimen pictured was isolated from soilwater at the base of moss growth.

Tuesday, February 23, 2010

In praise of tardigrades

Found on mountain peaks penetrating the ice sheet in East Antarctica to the Chihuahuan desert Mexico, as well as the on moss growing stubbornly in your lawn (from which the specimen pictured was isolated), tardigrades are remarkable creatures. They have been exposed to -272.95°C for 20 hours, to 130°G, to 6,000 atmospheres of pressure, and to excessive concentrations of most common gases and x-rays, and were still able to return to active life.

To survive under these under such extreme environmental stresses, tardigrades enter a state known as cryptobiosis. The mechanism of cryptobiosis is poorly understood; however a study on dessication (anhydrobiosis) of tardigrades in the University of Stuttgart in 2009 showed that tardigrades have evolved efficient DNA repair mechanisms which enable them to recover even after long periods of anhydrobiosis. Most impressively of all, in the FOTON-M3 space mission in September 2007, tardigrades were seen to survive exposure to both space vacuum and solar radiation during a ten day, low Earth orbit (258-281 km above sea level).

Morphologically, they have a bilaterally symmetrical body, covered with a chitinous cuticle, and four pairs of legs terminating in claws. Division into classes is based on the presence or absence of external sensory receptors. These classes are Heterotardigrada, Eutardigrada and Mesotardigrada. However, the grouping of Mesotardigrada is considered dubious. They are represented by only one species, Thermozodium esakii, found in a thermal spring in Japan which has since been destroyed by an earthquake. 

As a group, tardigrades are distinct enough to make their closest living relatives unclear and have been assigned phylum status. They are considered a sister group of the arthropods, forming (along with the onychoporans, the velvet worms) the Panarthropoda, which is considered as either a clade of the Ecdysozoa (molting animals) or the Articulata (animals with segmented bodies).

Fossil evidence indicates that tardigrades as we know them today have existed since the Cambrian period. Finds are few, but among others, four specimens were extracted from about 530 million year old Middle Cambrian “Orsten”-type rock in Siberia.

Monday, February 22, 2010

On mushrooms

Our daily intake of vitamin D (RDA 2.5 μg) is usually acquired through foodstuffs such as fish liver oil, egg yolk, liver and butter, or by cutaneous biosynthesis during sunlight exposure. Often these sources are not accessible. Dietary requirements may eliminate the aforementioned foods and the winter sun is often an infrequent visitor to some parts of the world.

Cep, Boletus edulis

Mushrooms provide an answer. They are excellent sources of vitamin D, with some containing up to 2 μg of the vitamin per gram of dry matter. They also contain phytosterols which have been shown to reduce cholesterol absorption, thus reducing overall blood cholesterol. Unfortunately most supermarkets and small stores in Ireland tend to stock only 1-2 cultivated types (generally button and portobella), and while specialist stores may stock a wide range, these may not always be close at hand. The answer lies in collecting of wild mushrooms. 

Common puffball, Lycoperdon perlatum

The overall consumption of wild mushrooms in Ireland is low, as it is in most European countries. In a 2007 study of wild edible Irish fungi in woodlands, Tom Harrington and Maria Cullen of the University of Limerick (on behalf of Coford), noted a change in this pattern. Previously mycophobic countries, such as Spain, now collect and consume many wild species of mushrooms. Indeed, Spain has set up nurseries of black truffle with oak which brings in over €4 million per annum. 

Ireland has 40 edible wild mushroom species. In the Coford study, 29 edible species were found between September and November in 53 forest sites. Harrington and Cullen established that broadleaf woodlands were more productive than coniferous types and that the most common fungi found were hedgehog fungus, honey fungus, wood blewit and ceps. This shows the variety and frequency of this free foodstuff.

Chanterelle, Cantharellus cibarius

The rise in interest in wild edible mushrooms is certainly a good thing; however it must always be tempered with a warning regarding poisonous species. Knowledge (or better yet, the presence of a knowledgeable person) of the differences between the edible and the toxic on a mushroom hunt is essential.

Thursday, February 18, 2010

Coral, crinoid and brachiopod fossils

The following corals and crinoids were found in grey limestone on the foreshore and backshore of beaches in Southern Ireland.
A Colonial Tabulate Coral
Septa of a Rugose Coral
TS of a Brachiopod Shell
Fragments of Crinoidal Cups and Columns
Crinoid Columns
Crinoid Columns
Solitary Rugose Coral
Solitary Rugose Coral

Solitary Rugose Coral

Tuesday, February 2, 2010

Fossils in Fountainstown

A guest post by Ken.

So we went to Fountainstown today to visit the beach. The search was specifically for fossils and interesting rocks. Got there around 10.30am and spent quite awhile there. First off we found a rock containing quite a few periwinkle type-fossils. I was fascinated and soon was on my way to looking for my own.

About half an hour later after cracking 10s of rocks and getting a lesson in geology along the way I found my first ever fossil (see below). I thought at first is was an ammonite. Looking now it is more than likely from the Gastropoda or Nautiloid classes.

I went frantically looking for others and we both found a good few more. It wasn't until returning to Carrigaline that we noticed how good they were. The second fossil showed a type of shell (below); possibly a Brachiopod or a bivalve.
My last find was a nice one even if a bit small. This was definitely from the Gastropod class (below).
So there you go. A great morning spent on the beach in Fountainstown and then on to the hotel for lunch.