Frechiella or A nautilus with an ammonite suture…

Frechiella subcarinata (YOUNG & BIRD, 1822), 8.5 cm diameter, Port Mulgrave, with a Dactylioceras fragment and a belemnite phragmocone in the aperture

Frechiella subcarinata (YOUNG & BIRD, 1822), 8.5 cm diameter, Port Mulgrave, with a Dactylioceras fragment and a belemnite phragmocone in the aperture

Frechiella is one of the rarest Yorkshire lias ammonites and in some respects also one of the oddest.

It comes from a so-called “aberrant” line of ammonites, previously thought to come from one subfamily Bouleiceratinae of the family Hildoceratidae,
but nowadays after some more analysis (Rouleau et al 2003) is being split up into the 3 subfamilies Bouleiceratinae (lower Toarcian),
Leukadiellinae (middle Toarcian) and Paroniceratinae (upper Toarcian, including Frechiella) but all still under Hildoceratidae.
All are much more common in the tethyan realm, and are rare “strays” into the north-west european faunal province.
All members show a characteristically reduced, sometimes “ceratitic” suture (named after the triassic ammonite genus Ceratites, which showed a similar suture).
Oxyparoniceras telemachi (RENZ), 2 cm This is a member of the same subfamily, but not found in Britain, but somewhat further south from Barjac in the south of France (and purchased by me).

Oxyparoniceras telemachi (RENZ), 2 cm
This is a member of the same subfamily, but not found in Britain, but somewhat further south from Barjac in the south of France (and purchased by me).

This is also the main diagnostic feature, otherwise one could easily confuse these very involute ammonites with a nautilus , especially when they are wave-rolled –
In fact, Frechiella subcarinata was originally called Nautilus subcarinatus YOUNG & BIRD, 1822 –
you can just believe that, if it weren’t for the very characteristic suture, and I guess some of you might now go checking the nautilus in their collections …
(and of course : Frechiella is an ammonite, not a nautilus !)
Well preserved specimen show a faint keel on a rounded, sometimes slightly rectangular venter, faint radial ribs, sometimes flat waves can be seen close to the umbilicus.
With almost all specimen I’ve seen (and that’s not many…) the body chamber is more or less crushed or imploded.
Frechiella subcarinata (YOUNG & BIRD, 1822), 10 cm, Hawsker Bottoms

Frechiella subcarinata (YOUNG & BIRD, 1822), 10 cm, Hawsker Bottoms

Frechiella subcarinata (YOUNG & BIRD, 1822) , the only Yorkshire species in the genus Frechiella found so far,
occurs only in the main alum shales, commune subzone, bed 54 (HOWARTH 1992).
It is one of the rarest Yorkshire coast lias ammonites, and many regard it as the “holy grail” of upper lias ammonites.
I had for a time almost given up on trying to find one myself, and bought an unprepared specimen, found at Port Mulgrave (the one pictured below the title),
from Mike Marshall in September 2003.
But as it happened – and doesn´t it always happen like this ?!  – a year later in September 2004 one twinkled up at me from the cliff debris on one of my favourite
spots around Hawsker Bottoms – this is the one pictured above – I have not found one since, not even a fragment.
AndyS

You can´t find everything or Buying fossils

Every collector endeavours to make his collection as complete as possible. Whatever your collection object, that goal becomes easier to achieve when you specialize on a certain sub-group. For me, this is ammonites, liassic ammonites, Yorkshire liassic ammonites. I do stray from that path once in a while and get tempted , e.g. when a species cannot be found in Yorkshire at all, for example Prodactylioceras davoei , or can be found in another preservation from another location, like the beautiful white Marston Magna Asteroceras, Xipheroceras and Promicroceras,  but that is really only the exception.

“Yorkshire liassic ammonites” is still large enough a topic to collect a lifetime and not find every species there is to find. Cycles in erosion patterns can mean that certain beds high up in the cliff will only fall every x years, and even then you have to be on the right spot at the right time. Some beds may not be accessible at all anymore, because they have been exploited a long time ago or it is forbidden to collect there anymore.  Some species may be that rare that only very few can be found at all. From the entries in my little red book  I have estimated that from October 1989 until April 2012 I spent 450 days collecting, spending our holidays in Yorkshire. Conservatively estimating 4 hours per day, I get around 1800 hours. Put this together with my other estimate that I´ve achieved to collect about 50 % of the known species so far, then you know what is possible when you do not live close to location…
Does the above all sound very apologetic to you ? OK, I admit it : I do buy fossils, especially ammonites from time to time. Nothing to be ashamed of, really. I´m just human.
When I buy, it´s usually from well-known UK dealers like
(Disclaimer : I do not get or expect any preferrential treatment from these guys to mention them here, so they enjoy a rare spot of free advertisement now !)
Here are a few of the ammonites I bought from them in the past :
Paltechioceras planum, 8 cm, from fossilsdirect

Paltechioceras planum, 8 cm, from fossilsdirect

This beautiful Paltechioceras planum from the Holderness Coast came from fossilsdirect. It is a species that should occur at Robin Hoods Bay as well, but I´ve never found it there yet.
The ribbing on this species is not as dense as on Paltechioceras tardecrescens.
Dactylioceras (Orthodactylites) cf. crosbeyi, 7 cm, from Yorkshire Coast Fossils

Dactylioceras (Orthodactylites) semicelatum, 7 cm, from Yorkshire Coast Fossils

This irresistible (I´m only human !) Dactylioceras (Orthodactylites) cf. crosbeyi came from Yorkshire Coast fossils. Those thick variants of the Dactylioceras (Ortodactylites) genus are ever so rare, this is a particularly nice specimen and also very nicely prepped.
Dactylioceras sp, 8 cm, from Natural Wonders / Fossils UK

Dactylioceras sp, 8 cm, from Natural Wonders / Fossils UK

 This Dactylioceras sp. (we´ll leave it there for the moment, that´s another story !) came from Natural Wonders / Fossils UK. It is a very interesting Dactylioceras variant with strong ribbing,
we think it comes from the ovatum beds and the type of nodule it´s in seem to confirm that- this is one I´d like to check against some museum holotypes.
I do sometimes buy from ebay as well, very occasionally you can get a bargain there, but you have to know what to look for, and bidding for really good stuff can sometimes be fierce, exceeding the price that you would pay in a shop, simply because the group of bidders is global.
AndyS