Article: A new phillipsastraeinid tetracoral from the Devonian of New South Wales
Publication: Palaeontology
Volume:
24
Part:
3
Publication Date:
July
1981
Page(s):
589
–
608
Author(s):
A. J. Wright
Abstract
Fromeophyllum climax gen. et sp. nov. is a phillipsastraeinid tetracoral from the Mount Frome Limestone near Mudgee, New South Wales, Australia, where it occurs over a stratigraphical thickness of 98 m, ranging between Dalejan (Early Devonian) and possibly Eifelian (Middle Devonian) strata. The subfamily assignment is based on a close similarity to Macgeea touti Pedder, which appears to be ancestral to F. climax. Silicified specimens show F. climax to be a polymorphic fasciculate form which undergoes up to three phases of parricidal peripheral increase. When basal structures are preserved, F. climax is mostly found attached to various types of fossil skeletons which offered a firm substrate above the muddy sea floor by sheaths of skeletal material. Calcareous specimens show a well-defined vertical series of horseshoe dissepiments outside which are horizontally disposed ranks which consist alternately of mostly horseshoe dissepiments and flat dissepiments. Outside this zone normal dissepiments are developed which are proximally and outwardly inclined. This outermost array of skeletal material often spreads down the side of the colony over the wall of the trunk, demonstrating the presence of a highly extensile edge zone and everted calyx. Polymorphism is manifest in the diameter and number of septa developed in each of the several generations within a colony.O N the western and southern flanks of Mount Frome (650 m) which is located 13 km east of Mudgee, New South Wales, Australia (text-fig. 1), the Mount Frome Limestone (Wright 1966) is well exposed. Despite the early discovery and recognition of this limestone and others in the area (Stutchbury 1852; Taylor 1879; Clarke 1978), little attention was paid to its rich faunas until the work of Game (1935). 'Game (1935, p. 209) preferred a Silurian age, in contrast to the Devonian age inferred by Clarke (1878, p. 16).