GuidesMagazineShopBuy FossilsJoin Hunts
Doggerfan
beatpete wrote:
Great stuff, Roger, you're a definitely an asset to this forum



Thanks very much Pete. It's an honour to receive such a comment.
Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
Continuing on here with the series on the continental Middle Jurassic fauna. Natural Bajocian outcrops or exposures at quarrys or pits are a rarity in my neck of the woods, so I either have to venture further afield or literally walk over fields in order to find something. The one exception is the Wutach area, but the few exposures there are not very yielding and I often don't find anything at all when I explore them and end up returning to the more fruitful Aalenian layers.
At least I have found a few things there, some of which I show below. I'm starting with these finds since they are stratigraphically directly above the upper Aalenian.

A359a.1.jpg 
Hyperlioceras sp. 8cm. Sowerbyi Oolite Formation. Discites Zone. According to an expert on the Middle Jurassic ammonite fauna, this is a transitional form between Graphoceras and Hyperlioceras. This species was the last of the Mohicans. After they died out the Graphoceratidae were no more.

A71a.2.jpg 
Fissilobiceras sp. 26cm. Ovale Zone. Wedelsandstein Formation. One of the last of the Hammatoceratidae. Not so well preserved but nevertheless worth keeping.

A531a.1.jpg 
Emilaea contrahens 20cm. Ovalis Zone. This one was a lucky split. As soon as I showed it in the German Forum, someone got in touch with me who was writing an article on the ammonite fauna of this family and I ended up donating it to a museum. They were nice enough to make a colored mold of it for me in return.

A537a.1.jpg 
Sonninia sp. 5cm. I don't know exactly which zone this is from, since I found it in a loose block in a stream.

The next one was a gift in return for a favor, so I know exactly where it comes from.

A183a.1.jpg 
Sonninia (Euhoploceras) adicra 16cm. Sowerbyi Oolite Formation, Laeviuscula Zone, Trigonalis Subzone. Found at Lauterstein-Nenningen in the north of the Swabian Alb.

Here are also some bivalves from these zones.

L93a.1.jpg 
Ctenostreon sp. 10cm. These guys ranged from the upper Triassic into the lower Cretaceous and are quite numerous in certain layers, so I'll be showing more of them every once in a while. I find them fascinating. They are one of my favorite bivalves.

L111.1.jpg 
Camptonectes lens 3cm.

L246a.1.jpg 
Liostrea ?erina 5cm. An oyster with its "trapdoor" still in place.








Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
Moving up in order now to the sauzi Zone. I'm only able to collect this zone from plowed fields in spring and autumn. Ammonites from this zone are uncommon in my area and I've yet to find one, but I have found some other things. Particularly the bivalves Ctenostreon and Actinostreon lie like potatoes on the fields ripe for the picking.

B68.1.jpg 
The brachiopode Cymatorhynchia sp. 22mm.

S8b.1.jpg 
A group of Serpula sp. tubes. 5x4cm.

L123a.1.jpg 
L123b.1.jpg 
Actinostreon marshii. 11cm. long. Formerly Lopha marshii. These are called cockscomb bivalves in German for obvious reasons.

L9c.1.jpg 
Here's a side view of another one.

L202.1.jpg 
Ctenostreon sp. 12cm.


Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
The humphresianum Zone takes its name from the ammonite Stephanoceras humphresianum. I've already posted some finds from Switzerland...

http://www.discussfossils.com/forum_posts.asp?TID=5097&KW=&PID=50708&title=finds-from-the-swiss-middle-jurassic#50708

...but in my area I can only rely on the fields. At least some ammonites pop up every once in a while.

A464a.1.jpg 
Dorsetensia romani 7.5cm.

A854.3.jpg 
Dorsetensia pinguis 4.5cm.

I have to take a break now. To be continued...





Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
A592b.1.jpg 
Teloceras sp. 3cm. Finding complete ammonites on a field is practically impossible. This is just the inner whorls of the phragmacone as calcite mold.

A591a.1.jpg 
Stephanoceras humphresianum. Somewhat larger at 7cm., but still just phragmocone.

A628a.1.jpg 
A baby Chondroceras gervillii 2cm. This one is small, but you can tell by the mouth aperture that it's complete.

Now for a few brachiopodes, which are quite numerous at this level.

B51.1.jpg 
B101a.1.jpg 
Two Cardinirhynchia ?acuticosta 2cm with a serpulide passengers.

B139a.1.jpg 
A strangely shaped Cardinirhynchia sp.

Now for a Megateuthis sp. belemnite which I sliced open.
Be67a.1.jpg 


If you keep your eyes open while crawling along on hands and knees, you can also discover a few gastropodes.
G137aa.1.jpg 
Eucycloscala praetor. 2.5cm.

G163a.1.jpg 
Orbonella ?plicopunctata 24mm. Complete with slit band opening.

G137a.1.jpg 
Orbonella sp. 2.5cm.

G109a.1.jpg 
Orbonella sp. 22mm.

G108.1.jpg 
Ooliticia phillipsii 15mm.

G119c.1.jpg 
Bathrotomaria subornata 3cm.

Here's a funny little fellow
S9.1.jpg 
Serpula convoluta 2cm.

Can't forget the bivalves again.
L254a.1.jpg 

Pseudolimea cf. acuticosta
2.5cm.


Finally some more views of various Ctenostreon, Actinostreon and at the end Trigonia.

L153.1.jpg 
L193b.1.jpg 
L193e.1.jpg 
L193f.1.jpg 
L205a.1.jpg 


L151a.1.jpg 
L151b.1.jpg 
L197a.1.jpg 


L190a.1.jpg 
L128_links.1.jpg 
L175aa.1.jpg 




Best wishes from the Lake of Constance. Roger.
Quote 0 0
valh
Hi Doggerfan!
I am amazed,wonderful specimens!
Valerij
Quote 0 0
Tom
Really impressive.
Great finds!!
Quote 0 0
Doggerfan
Glad you appreciate what's being shown. I'll be carrying on here later
with the zones of the upper Bajocian, but I'll close off the middle
Bajocian for the evening with two field finds from the niortense Zone.

A594a.1.jpg 
A465.1.jpg 
Caumontisphinctes sp. 4.5 & 5.5cm. repectively. The first one as calcite mold and the second with a good portion of the shell still intact.

Here's a third one that I'm adding here on an edit. I skipped over it since I found it on a field which normally yields Bathonian fauna.

A619a.1.jpg 
Strenoceras sp. 5cm.

Edited by Doggerfan 2014-02-26 23:05:51
Best wishes from the Lake of Constance. Roger.
Quote 0 0
beatpete
Great stuff, Roger!

Beatpete
----------------
Anywhere for little ammonites, twice as far for big ones!
Quote 0 0
Dirty Pete
Impressive stuff Roger, Oh to find a Trigonia like that, I only ever find casts.....
Cheers
Pete
Quote 0 0
Doggerfan
Thanks Pete. Yes, Trigonia has such a beautiful shell, doesn't it? Sometimes the preservation here is close to perfect. I'll be showing a complete sample in the next installment.
Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
Oops, sorry. What I meant was the one after next, since I'm starting the upper Bajocian at the bottom in the tetragona Subzone. The rest of the garantiana Zone with the Trigonias follows suit. My finds from this subzone are solely from fields within an hour's drive from my home.

A648a.1.jpg 
A457.1.jpg 
A818a.2.jpg 
Bigotites (Prorsisphinctes) ?pseudomartinsi. 7.5, 4 and 11cm. respectively.

A818b.1.jpg 
These are the inner whorls with Serpula on the back side of the last one.

And here is one which I cut in half. Photographed with a light source behind.

A819a.1.jpg 
A819b.1.jpg 

The next one was in a stone which I broke in two along with the ammonite itself. It was worth the repair though, since the shell is well preserved.

A781a.1.jpg 
Garantiana (Hlawiceras) ?quenstedti 8cm.

There are also always lots of brachiopodes lying in the furrows.

B86.1.jpg 
B119.1.jpg 
Rhynchonelloidella proxima

B55.1.jpg 
Loboidothyris perovalis

 

Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
Oops. I made another booboo. I'll have to revise my previous post in saying that the tetragona Subzone is rather at the top of the garantiana Zone than at the bottom. Sorry 'bout that.

Now I'm going to move us in a northeasterly direction into Bavaria. The small town of Sengenthal is to be found a few miles south of Nuremberg. A quarry which went out of business many years ago is on the outskirts of this locality: the Steinbruch am Winnberg. This quarry has become famous far over its borders for its incredibly well-preserved and diverse fauna from the upper Bajocian. Collectors swarm here from all over Europe on the few occasions during the year when the doors are opened for collecting in a section of the now-existing biotope. I've managed to make 3 or 4 trips there in the past and have never regretted it (except perhaps for the one time where it rained cats and dogs all day long). Although the digs are not quite as rewarding as they were back in the golden days, it's still worth a visit and you are guaranteed to come away with some nice things, since the overwhelming majority of the fossils have the shell intact.
I'll start by showing some of the plentiful bivalves to be found in the garantiana Zone there.

L230a.1.jpg 
L230b.1.jpg 
L230c.1.jpg 
L230d.1.jpg 
L230e.1.jpg 
The series of photos above shows a complete Trigonia interlaevigata from various angles.

L105._Sengenthal.1.jpg 
Ctenostreon pectiniformis 10.5cm.

L156.1.jpg 
Pleuromya donicata 4 & 2cm.

L185.1.jpg 
Pleuromya uniformis 3.5cm.

L157.1.jpg 
Pressastarte sp. 2cm.

L183.1.jpg 
Modiolus bipartitus 4cm.

L232.1.jpg 
Gervillella aviculoides 12cm.

L238b.1.jpg 
Opis (Trigonopis) similis inside a Grammatodon virgatus. The oolitic matrix is usually relatively soft and easy to prepare.

L239.1.jpg 
Melaegrinella echinata
3cm.







Edited by Doggerfan 2014-02-24 23:51:01
Best wishes from the Lake of Constance. Roger.
Quote 0 0
Dirty Pete
Again, wonderful Trigonia, is the 'parent' rock an oolite as the shell seems to be stuffed full of ooliths?
Thanks for showing.
Pete.
Quote 0 0
Doggerfan
Dirty Pete wrote:
Again, wonderful Trigonia, is the 'parent' rock an oolite as the shell seems to be stuffed full of ooliths?
Thanks for showing.
Pete.


You guessed it. It is an oolite, just like the parkinsoni Zone at this locality. This makes the preparation almost child's play. Here's another one on the matrix for you.

L141.JPG 
Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
As I've already implied, the air abrader slices through the oolitic matrix like it's butter, so on the way to preparing the larger finds, you often discover some of the small fauna which can sometimes be distributed in the stone like raisins in a cake. A few of them are pictured below.

G158.1.jpg 
Cryptaulax (Xystrella) echinata 1cm.

E22a.1.jpg 
E22b.1.jpg 
The sea urchin Menopygus nodoti 1cm.

B60.1.jpg 
The terebratulid brachiopode Loboidothyris perovalis 3.5cm.

B118.1.jpg 
Top right Ferrythyris ferryi 2.5cm. Top left Loboidothyris perovalis
Bottom right Rhynchonelloidella alemanica. Bottom middle Aulacothyris carinata. Bottom left Acanthothyris spinosa


Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
I'll close off the garantiana Zone now with a few typical ammonites, the most of which are microconches. I only dug once seriously in this zone and despite the good finds I just didn't have the good luck to find at least one macroconch.

A567.1.jpg 
Garantiana sp. 2cm.

A453.1.jpg 
A799.1.jpg 
Garantiana (Pseudogarantiana) dichotoma. All roughly 3cm.

A563.1.jpg 
Garantiana (Pseudogarantiana) minima 2.5cm.

Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
I spent the majority of my time during visits to Sengenthal digging in, or rather, prying up the parkinsoni Zone. The ammonites to be found in it are sometimes absolutely immaculate, so a collector's heart skips a beat just thinking about it. That zone is usually what he hits first and he usually ends up staying there all day. I've had the opportunity to view some incredible collections from here and mine is quite humble in comparison to them, but I'm nevertheless quite happy with the samples I've found.

A346a.1.jpg 
A425.1.jpg 
A832a.1.jpg 
Oxycerites aspidoides

A424a.1.jpg 
Oxycerites subcostarius

Many of the ammonites have crystallized phragmocones. Here is an Oxycerites which I cut and polished.

A356a.1.jpg 



Parkinsonia is abundant and is represented by a good number of species, two of the more common of which I was able to find.
A271.1.jpg 
A344.1.jpg 
Parkinsonia (Gonkolites) convergens

A274.1.jpg 
A278.1.jpg 
Parkinsonia parkinsoni.
The species which gives its name to both zone and formation.

Here are some cut and polished ones.

A291aa.1.jpg 
A343a.1.jpg 
A354aa.1.jpg 
A354b.1.jpg 



A562.1.jpg 
P.parkinsoni on the right together with Planisphinctes incognitus





Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
I forgot about this one.

bla.jpg 
Lobosphinctes intersertus with some serpulide passengers Mucroserpula sp.


Best wishes from the Lake of Constance. Roger.
Quote 0 0
Doggerfan
I'm nearing the end of the Bajocian chapter now and shall finish off with more of the fauna from the Parkinsoni Oolite at Sengenthal.

Brachiopodes:

B2.1.jpg 
Aulacothyris carinata 2.5cm.

B59.1.jpg 
Acanthorhynchia sp. 2cm.

B61.1.jpg 
Rhynchonelloidella proxima 2.5cm.

B83.1.jpg 
Cardinirhynchia ascita 18mm. at the largest.

B93b.1.jpg 
Acanthothiris spinosa 2cm.

Gastropodes:

G4.1.jpg 
Bathroromaria subornata 3cm.

G86a.1.jpg 
Pyrgotrochus cf. elongatus 3.5cm.

G89a.1.jpg 
G89b.1.jpg 
Orbonella cf. parkinsoni
3cm.

Bivalves:

L22.2.jpg 
Grammatodon ?subdecussata 3.5cm.

L145.1.jpg 
Plagiostoma cf. rigidula 3+2cm.

L2.2.jpg 
Chlamys textoria 3.5cm.

blabla.JPG 
Trigonia interlaevigata 7cm. Both valves from the same individual.

There's just one more thing to show before I sign off the Bajocian. It's a plate from the quarry in Landaville, Vosges, France which I aquired through a trade for some middle Jurassic ammonites. The parkinsoni Zone there has a completely different fauna since it was a lagoon at the time.

E63c.1.jpg 
E63a.1.jpg 
E63b.1.jpg 
Acrosalenia hemicidaroides var. bradfordensis. The plate measures 20x17cm. If you look closely you can also notice crinoid parts from Isocrinus nicoleti, which can also be found in articulated samples there.

Hope you enjoyed this installment.





Edited by Doggerfan 2014-02-27 10:28:55
Best wishes from the Lake of Constance. Roger.
Quote 0 0
beatpete
Great stuff, Roger, you're a definitely an asset to this forum

Beatpete
----------------
Anywhere for little ammonites, twice as far for big ones!
Quote 0 0
Write a reply...


Discussions on fossils, fossil hunting, rocks, locations, and identifying your finds.
(C)opyright 2019 - UKGE Ltd and UK Fossils - Contact us