Mostly wishful thinking – Hildaites murleyi

Small 2.5 cm Hildaites murleyi next to a small Cleviceras and a few ammonite aptychi and possibly belemnite hooklets (!)

Small 2.5 cm Hildaites murleyi next to a small Cleviceras and a few ammonite aptychi and possibly belemnite hooklets (!)

When it comes to filling a gap in our collection, we collectors become a bunch of wishful thinkers, easily taking the slightest hint that a specimen might be the sought after species as fact.  Please note that this explicitly includes myself, and I´ve got a feeling it is directly proportional to the time that gap is perceived to be open.

One of my examples in this area is the below ammonite, found in October 2010 at Hawsker Bottoms.
I was so ready to call it Hildaites murleyi, believe me, mainly for the fact that it exhibits a finer ribbing than the usual Hildoceras lusitanicum (see here). But a final niggle remained, the preservation just did not fit – it was a typical commune zone Hildoceras lusitanicum preservation, with a sugary pyrite/calcite shell, that was almost gone, and a pyritic internal mould with some replacement shell.

Finely ribbed 8.5 cm Hildoceras lusitanicum MEISTER from the commune subzone at Hawsker Bottoms

Finely ribbed 8.5 cm Hildoceras lusitanicum MEISTER from the commune subzone at Hawsker Bottoms

Hildaites murleyi is an exaratum/falciferum subzone ammonite on the Yorkshire coast and in my experience relatively rare.
I´ve only really got one Yorkshire specimen I´m 100 % sure of that it is Hildaites murleyi, and it is the one shown in the title picture.
You can´t beat a good ammonite association, even better one that is so diagnostic as the above one : The small ammonites next to the Hildaites murleyi are Cleviceras, this small 10 x 5 cm matrix sliver also has many small shiny black ammonite aptychi and possibly belemnite hooks, which are so typical for certain exaratum subzone beds.

When the opportunity came up to purchase a better sized, verified Hildaites murleyi from well known collector Arno Garbe via eBay,
I just had to take it, even though it is not a Yorkshire specimen, one has to do something to close that burning gap…

It was found at Hildesheim in Germany in the so called “borealis” nodules of the exaratum subzone, Hildoceras murleyi was previously named “Ammonites borealis”
by SEEBACH in 1864. Arno is well known for his craftsmanship in preparing shelled liassic ammonites and this one comes in a beautiful chocolate and
caramel coloured calcite shell:
Beautiful 8.5 cm Hildaites murleyi (MOXON) in a borealis nodule from Hildesheim/Germany

Beautiful 8.5 cm Hildaites murleyi (MOXON) in a borealis nodule from Hildesheim/Germany

Now when you closely compare the two ammonites you can see the difference immediately:

Direct comparison of inner whorls of Hildaites murleyi (left) and Hildoceras lusitanicum (right)

Direct comparison of inner whorls of Hildaites murleyi (left) and Hildoceras lusitanicum (right)

Hildoceras lusitanicum has a much more visible groove , and the smooth area next to the umbilical wall is much wider than in Hildaites murleyi, where the groove is almost non-existent and the ribs don’t fade out towards the umbilical wall – you see the same on the small specimen in the title picture.
Arno´s Hildaites murleyi certainly is a very beautiful (maybe even more beautiful than a Yorkshire specimen can be), well prepared ammonite, and very educational in showing the typical Hildaites murleyi features as well.
But, you know, it´s not from Yorkshire, and it´s not the same as found by myself … I´ll continue looking… 🙂
(and no, if you were going to ask, I did not get the Hildaites murleyi that Mike -by pure coincidence – posted earlier in his web shop – someone was faster !)

AndyS

 

Leave a comment

3 Comments

  1. Nick Hanigan

     /  May 5, 2015

    Hi Andy. An interesting post. Why do you think they are so rare? Could they be a variety of hildoceras and do you think people have them in their collection without realising?

    Thanks

    Nick

    Reply
    • Nick,
      Thanks – I think it´s just the species from the Jet rock that seem to be more rare than the other – not sure why though.

      Best regards,
      Andy

      Reply
    • Nick, sorry for the late reply. They are pretty rare and from another bed than the usual Hildoceras species, it’s not impossible though that there are specimen in collections that are not er ognized as the rarer species…

      Reply

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