Research

THE MYSTERIOUS CONULARIIDS

Conulariids are an enigmatic group of uncommon fossils that have puzzled paleontologists for a century and a half. Research has shown that they are most likely related to Cnidaria (the group that includes jellyfish, corals, and sea anemone). They are also a long-lived group go as far back as the Ediacaran (approximately 635 mya), surviving numerous mass extinction events before going extinct at toward the end of the Triassic period (245 mya) with 150 species. Conulariid fossils are found globally.

Conulariids are preserved as shell-like structures made of rows of transverse calcium phosphate rods (also called ribs), resembling an ice-cream cone with four sides that are connected by grooved corners.

There are exceptional instances in which the soft parts are preserved, showing tentacles coming out of the wide end of the animal (aperture) and that the narrow end (apex) had a holdfast.

While they are often preserved flattened from the pressures of being buried during fossilization, some have 3D preservation. Their lifestyle was likely living on the sea floor in groups with the narrower-ended holdfast anchored them to the sea floor while they fed with their tentacles.

The idea for developing this research page on conularids came from a 2023 donation to our Indiana University Paleontological Collections (IUPC). In 1978, Kathryn Filemyr accompanied her brother Richard on a field trip for his geology class. Led by Dr. John Warren at Thomas Jefferson College/Grand Valley State College, Kathryn, Richard, and students examined the Middle Devonian Jefferson Limestone in Sellersburg, Indiana where Kathryn found this conularid (pictured above/left/right), and subsequently preserved it in her personal collection. Decades later, Richard brought the conularid to our IUPC at the request of his sister. Kathryn's donation sparked a quest to document the number and diversity of conularid specimens that were housed in the IUPC, and this led to training undergraduates in collections management and research, as the students subsequently digitized this specimen and others and produced this research page.  Our thanks are extended to Kathryn, Richard, and to all donors who have contributed so generously to our IU Paleontology Collections.

In Indiana, conulariids are found in nearly every period exposed from the Ordovician Richmond Formation in Brookville, IN to the Mississippian Borden Group here in Bloomington!

IUPC has one of the top 10 largest published collections of conulariid fossils in North America (#5 after the Yale Peabody Museum, Cincinnati Museum of Natural History, University of Kansas, and Smithsonian Museum of Natural History) with 145 specimens and the largest collection of conulariid fossils from the state of Indiana including a holotype (first formally described and primary reference for a specific species of organism) of Ctenoconularia delphiensis.

The CBRC has tabulated all of the conulariid fossils in the paleontology collection and has produced 3D models of some of the exceptional specimens using photogrammetry equipment.

Brood, K. 1995. Morpholgy, structure, and sytematics of the conulariids. GFF, 177(3), 121-137.

Leme, J. de M., Simones, M.G., and Van Iten, H.  2010. Systematics and evolution of a problematic fossil taxon: the Family Conulariidae (Cnidaria; Edicaran/Triassic). Phylogenetic systematics and evolution of conulariids.

Simões, M.G., Rodrigues, S.C., Leme, J.D.M., and Van Iten, H. (2003). Some Middle Paleozoic conulariids (Cnidaria) as possible examples of taphonomic artifacts. Journal of taphonomy, 1(3), 165-186.

Van Iten, H. 1991. Evolutionary affinities of conulariids, p. 145-155; in Simonetta, A.M. and Conway Morris, S. (eds.). The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge