Recent prep results, numbers see text
You might have noticed, I´ve deviated from my usual schedule of posting an article about every 2-3 weeks…
There are a couple of reasons, none bad, which have kept me from posting.
Reason number 1 is that commitments from my daytime job have kept me unusually busy for January and February and this will stay that way at least until mid march,
so you´ll have to wait for a new full article until about 3-4 weeks time.
Reason number 2 is I´ve been working on several full articles, but due to my perfectionism I was not satisfied with what I could have posted…
In the “unfinished posts” queue is the first part of the Dactylioceras article, dealing with the lower toarcian Dactylioceras species.
When looking at some of the ammonites I was photographing (every little prep fault somehow gets exaggerated when you look through a lens…),
I found that most of them needed some form of re-prep to comply to the same standard I´ve been trying to adhere to for the book.
This is for example the reason why #7 in the photograph, a Dactylioceras (Orthodactylites) clevelandicum, went back to the top of my prep queue :
The inner whorls needed some more attention with the fine air pen and the air abrader – it had been found in 2002 and basically went straight to the drawer at that time.
Reason number 3 is I need to clean up my prep slate before I go for my traditional spring collection tour to make space for potential new finds,
so the proportion of time prepping was higher that the one on writing…
All of the ammonites (and other fossils) have been prepped last weekend, in case you´re wondering what they are here´s the list :
- Dactylioceras (Orthodactylites) tenuicostatum, 7 cm
- Double of Dacytlioceras commune, 5 & 4 cm, thanks to Dr. Mike Howarth for helping to correct my inital thoughts on this one…
- A Plagiostoma sp. bivalve, 6 cm, from the apyrenum subzone of the middle lias, a “first” for me, I´ve never seen one before from the Yorkshire lias…
- A combo of Amaltheus stokesi (5.5 cm) , Amaltheus bifurcus (2.5 cm) , Amaltheus wertheri (2 & 1 cm)
- Pleuroceras hawskerense, 6 cm
- Dactylioceras (Orthodactylites) semicelatum, 5 cm
- Dactylioceras (Orthodactylites) clevelandicum, 9 cm
Another article that´s in the “unfinished posts” queue for a long time already is about pathologies on Yorkshire coast liassic ammonites, for the simple reason that
literature about pathologies was somewhat thinly spread across a wide range of publications, most of the time with few pictures (so important for the amateur collector !).
But thanks to Prof. Dr. Keupp from FU Berlin this has now changed (http://www.geo.fu-berlin.de/geol/fachrichtungen/pal/eigenproduktion/Band_12/index.html) :
A brand new copy of his almost 400 page thick, large format, just released new atlas on cephalopod palaeopathologies has landed on my desk, I had only very little time to study it yet, but what I´ve seen so far is
spectacular (pictures galore !) and will surely set the scientific standard on this topic for years to come (unfortunately it is currently only available in german).
So through this new publication my “sick ammonites from Yorkshire” post will take a giant leap forward and will be published after the first part of the Dac post…
Posted by andysfossils on February 16, 2013
This is an Asteroceras blakei
SPATH, 1925 from Robin Hoods Bay, found by Keeley and Adrian on the 20th of April, 2011 (guess what, my little red book
told me that…).
They entrusted this 10 cm ammonite to me for the preparation using my air abrader. After securing the remaining shell with a bit of liquid super glue, to stop it from flying away in the air stream (it easily does that by the way) , I prepped it and it came out like this.
Asteroceras blakei SPATH, 1925, 10 cm
But this is not all that this little story is about, it´s more about finding out more about Asteroceras blakei.
I usually at least try to take a look at the original description of the author. As you can see from the name, the original describer of this species, Leonard Frank Spath, did name this ammonite in 1925.
In HOWARTH 2002 the ammonite was pictured and full details were given for the original describer and the year, a list of synonyms (Asteroceras marstonense SPATH is one), some museum references, and, in the references the name of the publication where SPATH described the ammonite :
“Notes on Yorkshire ammonites. The Naturalist, Hull, 1925”. The Naturalist, as I found out, is the periodical publication of the West-Riding Consolidated Naturalists’ Society and, later, the Yorkshire Naturalists’ Union. Some volumes (between 1865 and 1921) can be found at Archive.org :
They´re delightful reading, most is about fungi, lichen, spiders, birds, etc. but sometimes there is something about geology or fossils. If you open one of the volumes in Acrobat reader and search for “ammonite”, in the 1921 volume for example you´ll find some not so pleased remarks on BUCKMAN´s then new nomenclature in his “Yorkshire type ammonites” or the prohibitive cost of printing for some of his volumes, in the 1909 volume a short arcticle about “The ammonites called A. serpentinus”, some species of the Harpoceras genus, including a picture of the giant Harpoceras (then called H. mulgravium) that is now exhibited in Whitby museum. But no luck with the 1925 volume…
I sent out severall calls of help to the various forums I visit, but first to no avail. I had almost given up, when after almost 5 months later out of the blue I received a note from Dr. Rene Hoffmann, from the Ruhr University at Bochum, sending me copies of the two pages describing Asteroceras blakei – thanks again for that !
So here is that first picture of Asteroceras blakei SPATH, 1925 :
Asteroceras blakei, the original picture from “The Naturalist”, 1925
But that´s almost all that SPATH writes about this new species – I must admit I was somewhat underwhelmed for all the trouble it took to find this description !
Thanks of course to Keeley and Adrian, for letting me borrow, prep & photograph the ammonite !
Posted by andysfossils on June 27, 2012
I showed you a relatively large Radstockiceras buvignieri (from the collection of my friend Klaus) in an earlier post, now here´s the smaller Radstockiceras from my own collection :
Radstockiceras buvignieri, pyrite, 3 cm
This one is preserved in solid (stable) pyrite and came from the polymorphus subzone, together with a few other finely pyritized ammonites like Tragophylloceras numismale and Polymorphites sp. (more on these later…) Is this the same species as the larger version ? Preservation is certainly very different, the large Radstockiceras is preserved in grey limestone. I doubt my friend Klaus would forgive me if I broke open the large Radstockiceras he loaned me to check if the inner whorls are the same as (the outer whorls) of the smaller pyrite ammonite (if preserved at all…) – Imagine me giving him back a small bag of rubble, saying “Thankyou, here´s your ammonite back, I ckecked something on it, but it came to no result…” ! I guess there would have been a chance to do this – the large ammonite had been broken in the middle when found – but there is no photographic record of what the inner whorls looked like (I feel yet another blog article coming up – photographing your finds shortly after you´ve made them…).
I had put the pyrite ammonite towards Radstockiceras complanosum, especially since I had seen a picture of one extremely similar ammonite in HOFFMANN´s 1982 publication about the lower Pliensbachien of North-West Germany. There it was listed as Radstockiceras oppeli, a few years later SCHLEGELMILCH 1992 lists this as a later synonym of Radstockiceras complanosum :
Radstockiceras oppeli (SCHLOENBACH, 1863)
Radstockiceras complanosum (SIMPSON, 1855) -> since described earlier, this species has priority
HOWARTH 2002 goes even further and lists Radstockiceras complanosum as a synonym for Radstockiceras buvignieri :
Radstockiceras buvignieri (D´ORBIGNY, 1844) -> since described even earlier, this has priority
Since HOWARTH obviously had the opportunity to compare against SIMPSON´s holotype, this is what it is labeled now as well : Radstockiceras buvignieri
The full list of synonyms even contains different genera (Ammonites, Retenticeras, Metoxynoticeras) as well, painting a picture of more than 150 years of different authors in different locations working on potentially differently preserved ammonites, of (early) branching and (final ?) joining of species names.
Posted by andysfossils on June 9, 2012
Just a small selection of ammonite literature I´m using to write this book
When you start collecting ammonites seriously, you want to know what you have found. Most collectors early in their collecting life begin by picking up everything that looks like a fossil (just as I did) . Only later, when your drawers start to overflow up or simply because you are interested in one type of fossil more than in others, specialization will happen.
Chances are that for identifying your finds you´ve had one or more of the more general fossil books which cover everything from foraminifera to dinosaurs and mammals. For every fossil group these naturally can only show the most common representatives of that group – when you specialize, you will very soon get to the limits of these books, even for a fossil group such as ammonites, with a lot of very common representatives.
Now palaeontology is a science with hundreds of years of history and many palaeontologists specialized on ammonites and published their works about them.
A brief snip from my literature index, in my view with particular importance to the liassic ammonites in Yorkshire, Britain and elsewhere :
A brief snip from my ammonite literature index, spanning approximately 6000 pages
This constitutes an estimated 6000 pages of some rather specialized books and papers.
I have them all in my library and have read through many, but not all of them, some are just ad-hoc reference. But this is something only somebody as crazy as I am will do. You will have trouble getting access to many of these books and papers since many are out of print for a long time or in a pay-per-view internet library. For some you will have to pay collector´s prizes if you wanted a printed book, like the very popular Lias SCHLEGELMILCH that sometimes costs more on eBay now than what you had to pay after it was freshly published.
I think this is in the process of change at the moment as Open Access (see http://en.wikipedia.org/wiki/Open_access
) gradually becomes more accepted and more and more journals open up their back volumes to public access in the form of pdf files. Some scientists even publish a pdf copy of every paper they can scan on their own server – though there still may be copyright issues with newer publications on there (that´s why I won´t put the link on here).
As you can see in some of the titles, these monographs tend to be very specialized as well, only covering e.g. one family of ammonites, one specific stratigraphy, one location. These are publications that have been made with the scientist in mind, everything is as reproducible as possible, and in many cases statistical studies have been made to verify population boundaries as for example in HOWARTH´s Hildoceratidae monograph – I´m deeply awed by these works and not always completely without regrets of having chosen another profession. But this is not for everyone…
All this taken together amounts to one of the reasons I´m writing this book : I get a feeling that something “in between” is needed, something bridging the gap
between the specialist paper and the amateur collector that allows to get a decent overview of the Yorkshire ammonites without reading tons of papers.
And who knows how this project might turn out : Nowadays it´s just a difference of a few mouse clicks (OK a bit more) and you publish your paper as a real paper book, an e-book or an open access pdf file… although I must admit a real paper book is my absolute favourite option of these.
Posted by andysfossils on June 3, 2012