Carboniferous Corals From The Uk

[Ludwigia]

That's a beautiful sample, Tarquin! I just got back from a short holiday in Ireland where I managed to find some carboniferous corals, including Siphonodendron. I can post them here once I get them cleaned up.

[TqB]

Thanks, Roger! - I look forward to seeing them.

This is a glacial erratic from the Yorkshire coast, a diphyphylloid (no axial column) that I haven't firmly identified yet.

It's partly cerioid which, according to the Treatise, should rule out Diphyphyllum itself which is just phaceloid.

So that leaves it a diphyphylloid Siphonodendron - you need to work out the mode of corallite increase to be sure and I think that needs more sections.

Scale in mm.

Edited June 9, 2014 by TqB

[Ludwigia]

Hi Tarquin,

Here's one for starters. Michelinia favosites 7x6cm. from the lower Carboniferous at the Hook Peninsula. Is that Syringopora sp. growing on its backside or is that part of the structure of that coral?

PS. I just noticed I made a mistake saying I had Siphonodendron. I got it mixed up with Syringopora.

Edited June 12, 2014 by Ludwigia

[Ludwigia]

And here's a rather large Syringopora ?geniculata with a spirifid brachiopod riding on its back.

Edited June 11, 2014 by Ludwigia

[TqB]

Hi Roger,

Fine specimens, thanks for showing! That's a particularly beautiful Michelinia favosa, did it need much prepping? And yes, it's got Syringopora growing on it so perhaps it was overturned prior to burial.

Edited June 12, 2014 by TqB

[Ludwigia]

Hi Tarquin. Thanks for confirming the Syringopora. The prep was done solely with air abrader at the most about 60psi (4bar). There are sites along the coast on the Hook peninsula where they are quite common.

Edited June 12, 2014 by Ludwigia

[TqB]

I've just sliced this Siphonodendron, an erratic pebble from Cayton Bay, Yorkshire.

It wasn't very promising from outside and is somewhat crushed but has some nice detail, with silicified outer walls.

With part cerioid colony form, it's on the way to being a Lithostrotion.

(I like the intersecting structures in the third photo, a bit like a cubist painting).

Edited July 18, 2014 by TqB

[Wrangellian]

I must have missed this thread first time around, so have read from top to bottom just now - Beautiful stuff you guys (incl. Roger)!

[TqB]

Thanks, Wrangellian.

Here's one of my favourites - a glacial erratic specimen found recently on the Yorkshire coast (Robin Hood's Bay).

It's not supposed to be a rare species but this is only the second I've found as a pebble where other corals of similar age are common. That might partly be because it's hard to spot - I was lucky that it was wet at the time.

Palastraea (formerly Palaeosmilia) regia (Phillips). Probably Brigantian Stage.

As found :

Ground and polished (I haven't sawn this one):

[TqB]

Diphyphyllum sp. , erratic pebble from the north Yorkshire coast.

vertical section:

[squalicorax]

Very nice corals!

[TqB]

Thanks, Squalicorax!

I've just used this one in someone else's post and realised it wasn't here.

Caninia benburnensis. Namurian, Great Limestone, north east England. Picked up recently in a stream near an old quarry.

(Compare with Siphonophyllia on post 23 earlier on this page. Caninia doesn't have the bubbly lonsdaleoid dissepiments)

Edited August 23, 2014 by TqB

[TqB]

I picked this up today on the Yorkshire coast, a glacial erratic Diphyphyllum in a haematite rich matrix. The corallites themselves are very well preserved, some with a clear calcite infill that allows a 3D view.

12cm polished slice:

single corallite, 6mm:

dividing pair, 7mm:

[Roz]

Fantastic fossils and such excellent images!

[TqB]

Thanks, Roz!

[TqB]

This is the weird and wonderful heterocoral, Hexaphyllia marginata (Fleming).

Apart from one or two possible Devonian genera, all heterocorals are Carboniferous and placed in just two genera (the other one being Heterophyllum).

This specimen is from the Brigantian of Ayrshire, SW Scotland (courtesy of a swap with a friend).

Just 3mm diameter which is typical:

This is from the only occurrence that I have collected myself so far, from the Brigantian of County Durham, North East England.

It's not so well preserved internally but the external detail is good:

It's often not at all obvious that they're corals - this from the same Durham site:

[Auspex]

This is the weird and wonderful heterocoral, Hexaphyllia marginata (Fleming)...

Very, very interesting!

[TqB]

Thanks, Auspex, I'm glad someone agrees!

I've slightly reground it for a better shot:

(3mm diam)

[TqB]

Here is the other heterocoral genus, Heterophyllia - maybe H. granulata Duncan.

From the Namurian Great Limestone of Durham, UK.

Heterocoral septa are distinctive and their insertion is radically different to rugosa (although you need serial sections to work it out and I've not tried that!)

They're long and thin but I've only found transverse sections so far - about 5-6mm across.

Weathered surface:

Same specimen, about 1cm in:

(One characteristic of heterocorals is that they have longitudinal external ridges that follow the ends of the septa - this shows here although the outer layers are obscured by crystal growth. It's much more obvious in the previous Hexaphyllia.

In rugosa, the septa are marked by furrows on the epitheca.)

Edited November 19, 2014 by TqB

[Auspex]

Thanks, Auspex, I'm glad someone agrees!

I've slightly reground it for a better shot:

(3mm diam)

It looks a bit like okra!

[TqB]

So it does! - knew it reminded me of something . A fine case of convergent evolution...

[TqB]

This is both sides of a single slice taken from an Actinocyathus laticlavia colony from the Great Limestone, Namurian, Co. Durham, UK

The second photo is flipped so it corresponds to the other side - it's 15mm thick.

It passes through the point where the colony has been phaceloid for a while then becomes fully cerioid (i.e. starting with the corallites parallel but tending to be separate so they have round walls,then fusing together to form common polygonal walls).

This can also happen the other way around, the net effect being to have some layers of the colony with gaps in it.

Lower:

Upper:

Following the same corallites through the slice:

[valh]

Hi Tarquin! I am glad to see a new topic of Carboniferous corals from the Uk.

Edited December 4, 2014 by valh

[Triceratops]

Nice fossils!

[TqB]

Thanks, Valerij & Lyall! - these are on the UK Fossils forum as well but I'm putting some of the more interesting or striking ones here .