rangeomorph

plural rangeomorphs

1. Any organism of the clade Rangeomorpha, Precambrian (Ediacaran) sessile organisms resembling ferns, possibly descended from sponges and among the oldest known complex lifeforms.

   Rangeomorphs became extinct at the end of the Ediacaran, at or before 541 Ma,[…].

   2020, Michael J. Benton, editor, Cowen's History of Life, 6th edition, Wiley Blackwell, page 53

   2 more examples

   Previous comparisons of rangeomorphs with cnidarians or ctenophores now seem unlikely. The fact that both sides of the rangeomorph structure are essentially identical, is not consistent with the rangeomorph frondlet "representing the bases of an array of open tubes that housed polyps or other filter feeding organisms."

   2007, G. M. Narbonne, J. G. Gehling, P. Vickers-Rich, “Chapter 3: The Misty Coasts of Newsoundland”, in Mikhail A. Fedonkin, James G. Gehling, Kathleen Grey, Guy M. Narbonne, Patricia Vickers-Rich, editors, The Rise of Animals, Johns Hopkins University Press, page 59

   Although the possibility that they were passive “mattresses” holding symbiotic algae is plausible for the shallow-marine specimens of Australia, the oldest Ediacarans are the branching, frond-shaped rangeomorphs from Mistaken Point, Newfoundland, which lived without light in deep water (Narbonne, 1998).

   2013, Donald R. Prothero, Bringing Fossils to Life: An Introduction to Paleobiology, Columbia University Press, page 260