Enigmatic fossils elevates CMC’s Invertebrate Paleontology Collection to one of the best in North America
Posted On: 04/10/2017 - 12:15pm, Posted By: Brenda Hunda, Curator of Invertebrate Paleontology
An acquisition of over 200 specimens of conulariids from Dr. Heyo Van Iten, Hanover College, to the Invertebrate Paleontology Collection of CMC has elevated our collection of these enigmatic fossils to one of the best in North America, perhaps rivaled only by the Natural History Museum in London as the largest collection of conulariids in the world. Although conulariids are found in the Ordovician strata of the Cincinnati region, these particular specimens are from the Devonian Period (~390 million years ago) of New York State. Their large size and inflated, 3-dimensional preservation in life position makes these specimens an exceptional addition to our collections.
As far as fossil organisms go, conulariids are not well known by most people, even though they are important for understanding the evolution of early complex life on Earth. For a century and a half the phylogenetic affinity of conulariids was hotly debated. Recent specimens with exceptional soft-part preservation have provided valuable clues, placing these fossils within the Scyphozoans (true jellyfish), near the base of the Cnidarian (corals, sea anemones, and jellyfish) family tree. Modern scyphozoan cnidarians are characterized by a prominent medusoid stage and a relatively inconspicuous polyp stage, which conulariids are thought to represent. No other cnidarians are known to produce skeletal material composed of calcium phosphate however, so their evolutionary relationships remain a source of debate.
CMC IP62854, Conularia aff. C. desiderata from the Middle Devonian Otsego Member, Mount Marion Formation, Cobleskill, NY. This specimen (5.5 cm or 2.16 inches in length) is preserved in life position, with the tapered end pointed towards the substrate.
The Conulata fossil record begins abruptly in the Cambrian Period (~510 million years ago) and extends without significant break through the Lower Triassic Period (~245 million years ago). The conulariids are preserved as shell-like structures made up of rows of calcium phosphate rods, resembling an ice-cream cone with four-fold symmetry (four-fold symmetry is also found in scyphozoans – a feature that suggests their evolutionary affinity). New rods were added as the organism grew in length. Exceptional soft-part preservation has revealed that soft tentacles protruded from the wider end of the cone, and a holdfast from the pointed end attached the organism to hard substrates. The prevailing reconstruction of the organism has it looking superficially like a sea anemone sitting inside an angular, hard cone held perpendicular to the substrate.
A reconstruction of Conularia in life position. Image from Van Iten et al., 2012. Life mode of in situ Conularia in a Middle Devonian epibole. Palaeontology 56(1): 29-48.
Scientific researchers from around the world continue to recognize our collections as an exceptional library of the history of life on Earth. Acquisitions of unique specimens like these conulariids will continue to strengthen the importance of CMC’s Invertebrate Paleontology Collection for contributing to global studies of evolution, paleobiology, and paleoecology.