Major developments in conulariid research: problems of interpretation and future perspectives

Juliana de Moraes Leme, Marcello Guimarães Simoes, Sabrina Coelho Rodrigues, Heyo Van Iten, Antonio Carlos Marques


Renewed interest in conulariids has resulted in clarification of problems in the paleobiology of this group.
Discoveries of skeletal structures and specimens preserved in situ, coupled with cladistic analyses, have led to a revival
of Kiderlen's (1937) hypothesis that conulariids were polypoid scyphozoans or a sister taxon of this class. Until
1979, research on conulariids centered on the description of new species and on the erection of subgroups using phenetic
approaches. Few papers addressed the paleobiology and phylogenetic affinities of conulariids, and none employed
cladistics. In contrast, the 1980's saw the publication of major papers on the paleoecology of conulariids, and
during this decade the hypothesis that conulariids were benthic organisms was corroborated. Also, new ideas concerning
the affinities of conulariids, including the proposal that conulariids represent an extinct phylum, were presented.
During the 1990's, the problem of conulariid affinities was widely debated, with authors advocating either
that conulariids represent a separate phylum or that they were cnidarians. Near the close of that decade, certain advocates
of a cnidarian affinity argued that conulariids were most closely related to Cnidaria. Taphonomic evidence
indicates that conulariids were benthic animals originally oriented with their aperture opening upward and that
they attached to or were embedded in hard and soft substrates. To understand unresolved problems we recommend
that (1) conulariid specialists develop a standard morphological nomenclature based on rigorous definitions; and (2)
studies on conulariid paleoecology be carried out using a sequence stratigraphy approach.

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