Sea lily

Crinoids and other fossils

01

The grey-blue star shaped object that stands out in this image is an ossicle (part of a calcareous skeleton) of a sea lily or crinoid,

02

a marine organism that looks like a feathered flower and that was very common in the Triassic period.

03

The dark objects in the photo are fragments of other marine fossils. This rock was formed from sand made up of fragments of shells which were subsequently cemented together.

04

The “cement” is made up of predominantly orange calcite crystals between the fragments. Buried marine sediments almost always end up in underwater aquifers with mineral rich waters.

05

The calcite cement precipitates from this water, and this is the way almost all sediments turn into rock.

References: http://en.wikipedia.org/wiki/Crinoid

Look at the micro-fragments of fossil crinoids in Encrinite di Fanes images.

Name: Crinoids and other fossils in limestone
Classification: Carbonate rock, oolitic-bioclastic grainstone
Mineral composition: Calcite, Dolomite
Fossils: crinoids and other echinoderms, molluscs
Location:

Dibona refuge (46°32’1.61″N12°4’18.87″E)

Formation: Formazione di Heiligkreuz
Era: Lower Carnian (approximately 235 million years ago)
Depositional environment: Carbonate substructure