2.8" Silurian Fossil Starfish (Protaster) - New York

This is a beautifully preserved fossil starfish of the genus Protaster. The longest measurement of this specimen is 2.8", and it's nicely centered on 4.5 x 4.2" slab of shale. It comes out of the Rochester Shale in Middleport, New York. You won't find many starfish from this site available on the market.

Comes with an acrylic display stand.

Caleb’s Quarry is in the Rochester Shale Formation, which is a primary source of over 200 richly detailed species that tell the ecologic story of the Early Silurian. This famous strata is known for its especially beautiful and rare assemblage of echinoderms. The calcareous mudstones and grainstones were transported from the relic Appalachian Mountains. The mountains were uplifted and then eroded into the shallow but deepening, warm seas of the Atlantic foreland basin.

While the rocks around Lockport, NY have been worked for trilobites since the 1830's, the opening of Caleb's quarry in 1991 has significantly added to the quantity and quality of the material available. Working this quarry which spends much of the year under water is unquestionably difficult. Many hours of detailed preparation are required under the microscope to extract and repair the trilobites which are found there.

Brittle stars are seafloor denizens belonging to the genus Protaster. These echinoderms are ornamented with flexible, whip-like arms that lurched them across the sea floor as one arm would have pressed ahead, and the other four acted as two pairs of opposite levers, thrusting the body forward.

Protaster is in the class Ophiuroidae, and are closely related to starfish. The ophiuroids diverged in the Early Ordovician, about 500 million years ago, resulting in over 2,000 species of brittle stars living today. The Rochester Shale is known for the excellent preservation of Protaster detail in its Lower Silurian strata (425 mya). They often fell apart after death, making a cluster of intact specimens a rare discovery.

There are several fascinating details regarding the Ophiuridoid body plan:

  • A brittle star's skeleton is made up of embedded ossicles, which are microcrystals of calcite arranged in a three-dimensional lattice known as a stereom. Occicles fuse together into an armor-like test which forms part of the endoskeleton.

  • There is a space between the crystals that together produce a light and tough, honeycomb structure.

  • Modern Ophiurides establish that Protaster had no eyes, or other specialized sense organs. However, they likely had several types of sensitive nerve endings in their epidermis.

  • Tube feet might have sensed light as well as odors.

  • The disk of Protaster contained all of the internal organs that conduct digestion and reproduction.

  • The underside of the disk contains the mouth, which is also the anus. Ingestion and egestion occur in the same area.
  • FOR SALE
    $695 $625
    DETAILS
    SPECIES
    Protaster sp.
    LOCATION
    Middleport, New York
    FORMATION
    Rochester Shale
    SIZE
    Plate: 4.5 x 4.2", Starfish: 2.8" wide (longest measurement)
    ITEM
    #232056
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