Simplified, wall-based morphology of a new Aptian coral and discussion of contrasting opinions on the taxonomy of similar corals

A new colonial coral, Monopachyphyllia roniewiczae gen. et sp. nov., from the upper Aptian carbonate platform of the Persani Mountains (Eastern Carpathians, Romania) is described. This densely branching (subphaceloid) coral has a very simple morphology. The thick wall is the dominant skeletal element and even attains 1/3-1/2 of the diameter of the entire corallite (up to 2.5 mm in diameter). The wall is developed prior to septa and is interpreted as a pachytheca. There is only one septum or very few septa, usually developed as short septal ridges. The septal apparatus, like in many other wall-based corals, is far from the traditional scleractinian septal pattern and septal insertion. The new coral is included in the suborder Pachythecaliina, provisionally into the family Carolastraeidae, superfamily Heterocoenioidea. The contrasting opinions on the systematic position of morphologically similar corals are discussed. Wall-based corals (family Zardinophyllidae, superfamilies Amphiastreoidea and Heterocoenioidea) are morphologically perhaps the most unusual post-Palaeozoic corals, with diverse taxonomic approaches. They are classified into the suborders Heterocoeniina, Amphiastreina or Pachythecaliina and placed in the order Scleractinia or in the extinct order Hexanthiniaria.

Automated summary

The newly discovered coral, Monopachyphyllia roniewiczae gen. et sp. nov., is a densely branching (subphaceloid) coral with a simple morphology from the upper Aptian carbonate platform of the Persani Mountains in Romania. The coral's thick wall is the dominant skeletal element, with only one or very few short septal ridges. It is classified in the suborder Pachythecaliina, provisionally into the family Carolastraeidae, superfamily Heterocoenioidea, showing contrasting opinions on its systematic position.