Androgynoceras maculatum, 8 cm, split nodule as found. The end part of the body chamber is on the negative part of the nodule and had to be transfered to the positive side.
Androgynoceras maculatum, 8 cm, with complete mouth border after preparation
The secret to achieving completely preserved ammonites is – do as little as possible in the field. The highest risk of loosing bits of the ammonite is when you work it with the crudest tool you have : Your hammer !
The ratio of ammonites on the Yorkshire coast preserved completely is relatively high, so here are some clues to increase your success rate of getting them into your collection that way :
- Recognize it as early as possible : When you find a likely looking nodule, don’t just whack it, instead take your time looking at it from all sides to see if any part of an ammonite is showing. If it does, and the nodule is not too heavy to carry, just bag it and take it home.
- If there is no outward sign of an ammonite in a likely looking nodule, don’t just whack it to split it through the middle : A perfect split is a very rare thing, and beach prepping is the worst sin an ammonite collector can commit IMHO (and I´m guilty of trying it myself sometimes, but less so in the last years). Instead try to “peel” the ammonite : Whack it very slightly around the edges, splitting off only small amounts of matrix, preferably in shards, turning it while you do so and observe if an ammonite becomes visible after every blow of your hammer. If it does, bag it and take it home
- And one of the most important advice of all : Stop hammering before the last blow 🙂
- Should during this process any part of the ammonite be split off : Do not throw the split off pieces away, even if they seem insignificant, try to glue them back on right away , if it’s a simple break. I carry both liquid and gel type super glue with me for this purpose in my collecting rucksack. I have found that many times the split off piece contained the mouth border, because I misjudged its position in the matrix. Don’t try to glue complex breaks in the field though, instead carefully wrap the broken off pieces and take them with you.
- Complete the job, when you find a likely looking nodule – don´t stop after the first blow of the hammer does not reveal anything interesting.
I´ve found many nice ammonites in half nodules that still had plenty of room, but had been left “for dead” by other collectors. It can sometimes also be interesting to split large solitary body chambers of nautiloids or large ammonites looking for smaller, potentially well-preserved, washed in ammonites or even inhabiting crustaceans…
Haugia in discarded nodule after another exploratory blow with the hammer…
Prepped Haugia variabilis, 7.5 cm, in 16 cm nodule
- Use enough wrapping material so that the pieces don’t rattle against each other in your bag/rucksack/etc. I’m using bubble wrap recycled from used jiffy bags – they make a nice pouch to put your fossil into.
- Once you are at home, you have all the time in the world to glue any complex breaks, wash the nodule, think about your prep strategy and execute it leisurely. It can sometimes help to mark the position of the ammonite on the outside of the nodule before you glue any pieces back on, especially when the nodule completely hides the ammonite when the pieces are glued back on. Who knows when you will find the time to prep it – until then you might have forgotten what the position of the ammonite is in the nodule.
Nodule with Zugodactylites – approximate position of the ammonite marked before glueing the nodule.
Nodule with Zugodactylites braunianus, 8cm, complete with mouth border after preparation
- While prepping, try to find the position of the aperture first. Always prep the outermost whorl following the direction of the aperture, not against the open aperture – you would not be the first one to find you’ve just prepped away the aperture while following the next whorl in the wrong direction…
- Take your time prepping the specimen. Sometimes, especially when you’re relatively new to prepping, it is better to practise on not so well-preserved specimen, and leave the better preserved ones til later, when you have gained more experience.
Double Ovaticeras ovatum (8 & 7.5 cm) from the core of a septarian nodule. The smaller specimen split off with the wrong side and had to be re-affixed to the matrix after prepping from the other side as well – it was found in 2000 and finally prepped complete in 2014…
- It takes time getting used to an air pen, and I’ve ruined many good ammonites because I was too eager to try the new tool…
- Don’t prep in a rush – it’s no good trying to finish that ammonite in the short timeframe before you need to pick up your kids/lunch starts/your favourite TV series starts etc… I’ve found that my prepping is best when I’m relaxed and my mind is at peace.
- If there are other faunal elements like bivalves, gastropods, crinoid pieces etc on the piece – leave them there, don´t try to get your ammonite on as little matrix as possible, sometimes these combinations of different types of fossils are much more beautiful (and scientifically interesting) than a single ammonite.
Nodule with 1 Eparietites ammonite and 1 Cardinia bivalve showing after first blow with hammer.
The soft nodule would have been obliterated after another blow…
Nodule with multiple Eparietites ammonites, Cardinia bivalves and a crinoid stem, width of nodule 11 cm
It only takes a little more care and a little more patience, but it can mean the difference between a mediocre and a great ammonite specimen…
AndyS
Yorkshire Ammonites (and other fossils ) revisited 