Anyone found a good fossil? | The Octopus News Magazine Online
  • Thanks for visiting! TONMO is the world's greatest online cephalopod enthusiast community, with interactive content going back to May of 2000, and a biennial conference. If you'd like to join in on the fun, become a TONMO member -- it's easy and free. Follow us on Facebook and Twitter for more cephy goodness.

Anyone found a good fossil?

WhiteKiboko

TONMO Supporter
Supporter
Joined
Feb 15, 2003
Messages
2,702
Location
Charleston
#3
all i have as far as fossils are concerned are just bivalve pieces and some augers...not really exciting, dont knowq much about them and theyre not cephs.... :|
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#4
Here is a fossil I found, from the Ordovician (about 450 mya) of Utah. You can see why they call Nautilus a living fossil. This is Plectolites, at least a fossil of the shell. Most of the chambers were broken and got filled with seafloor sediment, the left side is missing altogether. The chambers in the very center were still hollow when the sediment was turned to limestone, and latter the void was filled with calcite crystals, this destroyed the septa. The Siphuncle is a little different than in Nautilus

A fairly large file (196K) for detail

:ammonite:
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,034
#5
Wow! That's a beauty!

It's amazing to thing how similar this nautilus is to the modern species. I wonder which group of nautiloids it belonged to? According to my references the order of nautiloid that gave rise to our modern species did not appear until the early Devonian. So if yours is from the even more ancient Ordovician then it must belong to a separate long extinct nautiloid order.

Yet it is so similar! Amazing. I'll see if I can find out some info on Plectolites.

Phil
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,034
#7
That is a fantastic find.......do you find stuff like this regularly? Do you keep the fossils or sell them on?

Totally jealous!
 

tonmo

Titanites
Staff member
Webmaster
Joined
May 30, 2000
Messages
9,275
Location
Pennsylvania
#8
Yeah, seriously 8) -- how and when did you find that one?
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#9
Hi Guys!
The Goniatites are all in a single concretion. I found it in a wash after a gully-washer washed it out. It is the only concretion of that age I have found that still shows the nacreous luster of the original great-great-grandmother of pearl. I watch the National Weather Service page all the time and if I see a good storm go over that area, then I go see if any more wash out.
I usually keep the good ones an leave the others for other collectors. They are found on US Public Land (BLM) so I can only collect them in reasonable quantities, for personal use, and cannot sell or trade.
:ammonite:
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#10
It's hard to take a picture of the nacre in normal light, so I took a picture of a small piece of broken shell from the same concretion, then took a picture under the microscope with the light just right to show the colors. This is a piece of shell from Goniatites multiliratus, you can see the small ridges (lirae) that gives it it's name.
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,034
#11
If anyone is wondering why these ammonoids do reflect the light so beautifully as demonstrated in Kevin's picture above, it is because the shell of the ammonoid was composed of alternating layers of aragonite and conchiolin. The mantle secreted each layer as the creature grew and added chamber following chamber to its shell. Aragonite, composed of vertical prisms reflected light at a different wavelength to the conchiolin below. With four or five layers this means that intact shells of ammonoids often exhibit a rather nice subtle rainbow effect.

Ammonoids are found in many different colours, but this is an artefact of the type of mineral that precipitated into the gaps in the cells of the creature during the process of fossilisation. So a greenish ammonite does not necessarily mean that was the colour of the creature when it was alive. It seems highly likely that the ammonoid would have employed some form of countershading as a defense, much like the nautilus, though the exact form of which is anyones guess!
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#12
Thanks for that great explanation Phil,

Here is another picture from the same concretion, I believe this is a shell fragment from an orthocerid nautiloid. I don't know why but it seems the fragments are alot more colorful than the shell on a complete fossil.
:ammonite:
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,668
#13
Can anyone help me out with this ammonite. It is unlocalised (was just given to us yesterday). I'd love to know what it is (genus maybe, if possible), how old it is and where it has come from (if any of this is possible). It could have come from New Zealand, but it could have come from Mars.

It is rather distinctive. It's greatest dimension is 24cm (to the end of that pretty bizarre spike). Oooops, Phil has just corrected me - 'spike' = lappet. I should stick to squid and octopus :biggrin2:

Cheers
Steve
 

Clem

Architeuthis
Supporter
Joined
Apr 6, 2003
Messages
1,839
#14
Steve,

I found another lappet-bearing ammonite, online. Of course, the image was posted sans identification, but it makes for an interesting comparison with your new fossil. You can see the outline of the bisected lappet in the stone, extending to the edge of the photo.

Clem

ps: I had no idea the proper term was "lappet," either.
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,668
#15
Thought I'd post another image of some more stunning ammonites that have 'turned up' on the desk of late.

Upper left: Phylloceras sp. Albian (Cretaceous), Madagascar.

Lower left: Lamberticeras sp. Upper Calvian (Jurassic), Russia.

Lower right: Hoploscaphites nicolletii. Fox Hills formation, South Dakota (Late Cretaceous)

Upper right: Desmoceras cf. mahabobokensis, Albian (Cretaceous), Madagascar.

There are some other truly stunning bits and pieces, images of which I'll post another time (they're actually in the display cabinet at home :madsci: ). I really have been spoilt lately.

Cheers
O
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,034
#16
Steve O'Shea said:
Oooops, Phil has just corrected me - 'spike' = lappet. I should stick to squid and octopus.
Looking at this again actually I think that this form of spike on the aperture is called a spine. How original! :oops:

Lappets were lobes that projected from either side of the aperture, so I was completely wrong. I should stick to watching TV from the seventies!

Still not having much luck in identifying the specimen, hopefully when I get this CD-Rom on fossil Mollusca soon it may be on there.
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#17
Quoting most of this out of the treatise: A ventral extension of the peristome (apertural margin) may form a ventral lappet; or the ventral extension may be developed as a long, tapering rostrum.
More common are the paired lateral lappets.
As for an identification, Mortoniceras of the Early Cretaceous has the same kind of mature modification, but it has strong ribs covering it's shell. Pectinatites from the Late Jurassic also has a rostrum like that but it has ribs also. The fossil looks alot like Oxytropidoceras from the Cretaceous, but I don't know what the mature aperture looks like. Need more input for better I.D., any sutures visible?
The other fossils are great, do you have I.D.'s and locality info. on them?
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#18
Steve O said:
Upper left: Phylloceras sp. Albian (Cretaceous), Madagascar.

Lower left: Lamberticeras sp. Upper Calvian (Jurassic), Russia.

Lower right: Hoploscaphites nicolletii. Fox Hills formation, South Dakota (Late Cretaceous)

Upper right: Desmoceras cf. mahabobokensis, Albian (Cretaceous), Madagascar.
Architeuthoceras said:
do you have I.D.'s and locality info. on them?


Duh!!!!! :oops:
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,668
#19
Architeuthoceras said:
As for an identification, Mortoniceras of the Early Cretaceous has the same kind of mature modification, but it has strong ribs covering it's shell. Pectinatites from the Late Jurassic also has a rostrum like that but it has ribs also. The fossil looks alot like Oxytropidoceras from the Cretaceous, but I don't know what the mature aperture looks like. Need more input for better I.D., any sutures visible?
Kevin, Phil, Clem, I'll get back to you on this one, but it will be a couple of days away (full swing on something else right now). The shell has many apparent low-profile/gently undulating ribs, but no sutures are apparent. Ta for the input. It's great having a fossil forum!!
Cheers, O
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,405
Location
somewhere under the desert sky
#20
Here are some pictures of an excavation I did a few years back. You can see a map of the excavation at this link "map"
The old guy in the picture is me. These are ceratitic ammonoids from the Early Triassic, approx. 240mya, the first picture shows a closeup of one of the sutures.

Enjoy :ammonite:
 

Members online

Monty Awards

TONMOCON IV: Terri
TONMOCON V: Jean
TONMOCON VI: Taollan
TONMOCON VII: ekocak

About the Monty Awards