Primitive echinoderm - solved!!! + Hyolitha + Orthocerida...

Spectacular complete specimen of Nimchacystis agterbosi. In addition, the plates contain several specimens of hiolites (Hyolitha) and a specimen of an indeterminate orthocerid. Nimchacystis is a primitive and enigmatic echinoderm that lived during the Ordovician. The specimen is perfectly preserved; the body, the appendage and the dististele are visible. The animal Nimchacystis is a primitive echinoderm of the group Soluta. Nimchacystis had an oval body, a feeding appendage inserted laterally, and a twisted and flattened dististele. These animals are interpreted as active epibenthic feeders that feed on detritus and use their dististele to drag themselves across soft substrates. Also preserved are several specimens of Cavernolites senex, a primitive and enigmatic hiolite (Hyolitha) that lived during the Ordovician. The specimen is perfectly preserved. Hyolites (Hyolitha) are a class of small, conch-shelled lofoforates that lived in the Paleozoic era. Their fossils range from the early Cambrian to the end of the Permian. Their calcareous shells, probably aragonitic, are conical, with triangular or semicircular cross-sections and usually flattened on the ventral side. They possessed a cover or operculum, normally articulated. The taxonomic position of hyolites has always been uncertain, until in 2017 it was determined that they belong to Lophophorata, a group that includes brachiopods and bryozoans thanks to the study of specimens that preserve soft-tissue impressions. The Cavernolites animal led solitary, epibenthic, semi-sessile habits, i.e., they lived on the seabed substrate with very limited mobility, and were suspension feeders, feeding on suspended particles in the water captured with the tentacles of the lophophore. There is a plate and a counterplate. Specimens with this preservation are extremely rare. The contrast between the fossils and the matrix is spectacular. The extraordinary preservation of the fossils allows observing in great detail the delicate structures of Nimchacystis and Cavernolites. The preparation of the specimens has been extremely laborious, as the fossils are extremely delicate. A specimen worthy of a museum. Measurements: Nimchacystis: 70 x 15 mm Indeterminate orthoceratoid length: 45 x 15 mm Plate 1: 1182 g; 17 x 13.5 x 3 cm Plate 2: 678 g; 14 x 13 x 3 cm Plastic stands included. The Fezouata formations outcrops, near the Moroccan town of Zagora, are yielding a rich and varied fossil record with extraordinary preservation, to the point that soft parts or soft-bodied animals are recorded with some frequency. This type of preservation is similar, though later in time, to that of the famous Burgess Shale (Canada). These fossils are dated between 480 and 472 million years ago. Then Morocco was an ocean and it lay near the South Pole.

Schätzpreis:€160

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