470-Million-year-old black corals from China

Area of Science:

• Paleontology
• Marine Biology
• Evolutionary Biology

Background:

• Antipatharian coralla (black corals) have unmineralized skeletons, making their fossil record scarce.
• Previous research relied on molecular data to infer the evolutionary timeline of Anthozoa.

Purpose of the Study:

• To report the discovery of previously unknown phosphatic antipatharian fossils.
• To use fossil evidence to support or refine molecular phylogenetic predictions for Anthozoa.

Main Methods:

• Geological excavation and collection of fossils from the Fenxiang Formation, Hubei Province, China.
• Morphological analysis of fossilized coralla, including spinosity and branching patterns.
• Dating of fossil finds using geological context (early Floian, ~470 Ma).

Main Results:

• Abundant phosphatic remains of at least two antipatharian species, including Sinopathes reptans, were found.
• The fossils exhibit a dominant encrusting basal part with chaotically ramified branches, differing from modern species.
• The early Floian age of these fossils aligns with molecular clock estimates for Anthozoan phylogeny.

Conclusions:

• The discovery provides the first direct fossil evidence for early Ordovician antipatharians.
• The findings support the hypothesis that antipatharians predate the diversification of scleractinian hexacorals.
• The unique morphology suggests a plesiomorphic state for these ancient black corals, potentially linking them to Late Cambrian problematic fossils.