Oxfordian echinoids of Bałtów

Abstract

The autecology of echinoids from the Middle Oxfordian coraliferous limestones of Bałtów (NW margin of the Holy Cross Mountains, Central Poland) is discussed, as aparent from the morphology of tests, ambulacral pores for tube feet, and spines. Inferred is mode of life, locomotion, and feeding, as well as the diet of the taxonomically recognised three species: [i]Paracidaris florigemma[/i] (Phillips, 1829) – spines only, [i]Glypticus hieroglyphicus[/i] (Goldfuss, 1826), and [i]Hemicidaris merryaca[/i] Cotteau, 1850, the latter reported for the first time in Poland. The phenotypic convergence is indicated of such species as: [i]P. florigemma[/i] and extant [i]Eucidaris tribuloides[/i] Desmoulins, 1835, of Florida and the Caribbean, as well as[i] G. hieroglyphicus[/i] and extant [i]Colobocentrotus atratus[/i] (Linnaeus, 1758) of the Indo-Pacific. Environmental conditions, under which the Bałtów echinoids lived, are concluded as extremely shallow marine (shallow subtidal up to low-intertidal), connected with the Bałtów coral patch reef nearby.