Juvenile heteromorph

Another small heteromorph from the Cretaceous Mancos Shale. This one has the body chamber preserved so it is freshly hatched or up to a few weeks old. 1mm diameter at widest point.

SR2 Anasibirites Bed

Like at all other localities, about as thick as the hammer. The lower beds at this locality are a lot less fossiliferous than at any other, they have also been baked by the nearby igneous intrusions, so I don't think they are worth collecting in detail.

A closeup. All the small circular spots are drippings from the Pinyon tree above

Tirolites ?

? Tirolites body chamber cast

From above the "Clam Wall" and below the "Spathian Gap", geographic outcrop nicknames that don't mean anything to anyone unless you have a copy of my field notes from 15 years ago, sorry. Even below M109 of anothers' notes. Not a very good fossil, but it may be important.

Calcite Heteromorph

A small portion of a heteromorph ammonoid, possibly Allocrioceras. This thing is only about 1.5mm long, photo taken through the eyepiece of my microscope. Dorsal side toward viewer, without impressed zone so it was completely evolute and probably open whorled, not enough preserved to tell if it was helical or not. From the Upper Cretaceous Mancos Shale, lower Upper Turonian Scaphites whitfieldi Zone.

Rudolftruempyiceras Guex & Bylund 2010

The name Boreoceras Dagys & Ermakova (1988), has been replaced with Rudolftruempyiceras Guex & Bylund 2010, Family Columbitidae, see Guex, J., Hungerbuhler, A., Jenks, J., O’Dogherty, L., Atudorei, V., Taylor, D., Bucher, H., Bartolini, A., 2010, Spathian (Lower Triassic) Ammonoids from Western USA (Idaho, California, Utah and Nevada), Memoire de Geologie (Lausanne), No. 49, on page 29. The name Boreoceras is used for an Ordovician Endocerid Nautiloid by Miller & Youngquist (1947). The ammonoids in this old post and this update, will probably be referred to Xenoceltites and not the new genus.

Link

Cephalopods - Present and Past

Cephalopods - Present and Past:



Stephen, D.A., Bylund, K.G., Bybee, P.J. and Ream, W.J.: Ammonoid beds in the Lower Triassic Thaynes Formation of western Utah, USA, p. 243-252

In the 20 years since I located the Triassic fossil bearing beds in the Confusion Range of western Utah, I have only co-authored papers on sponges and gastropods. Now, a paper on the Ammonoids. The first of many I hope.

Calcite Replacement

Calcite replaced ammonoid shell
(is that really angular coiling in the umbilicus?)

another showing partial suture line

Early Triassic Lilliputians

Lilliputians

Just for comparison, the typical size of previously studied Early Triassic gastropods with a Dime for scale.