Genus: Fenestella Species: Not known Location found: Baton River
Bryozoans were prolific during the Devonian Period and at that time must have been one of the most abundant forms of life in the oceans. The branching forms were the most common; encrusting forms are often associated with brachiopods, and bryozoans may form dense meats on brachiopod shells. Fan-like forms tend to be associated with crinoids.
In New Zealand, in the Reefton and Baton River formations, Fistulipora cf. infoliata, Lioclema(?) reeftonensis and Fenestella are all listed from the limestone beds in the Reefton Formation by Bradshaw and Hegan (1983), while Shirley (1938) lists Hederella sp., Fenestrellina cf. exilis, Polypora sp. and a few less certain species from the Baton River Formation. How reliable some of these identifications are is not clear. Shirley's (1938) identification of Fenestrellina cf.exilis, for example, was made at a time when the use of the genus name Fenestella had been suspended in favour of Fenestrellina. In 1960, this decision was reversed and Fenestrellina was excised, instead, and the name Fenestella reinstated. Since then, the species has been renamed again, to Rectifenestella cf. exilis. All this shows the pitfalls of palantaeology for the amateur!
The specimens shown above and to the right are from the Baton River Formation; the one shown below is from an unknown location but from the character of the sediments may well be from Reefton. All of them are tentatively ascribed to the genus Fenestella, which has a fan-shaped form. If this is accurate, the Baton specimens would seem to be the first record of the genus from that location, though as noted above it has been found in the Reefton Formation. Without better specimens amd comparative materials, however, these identifications remain uncertain.
LPB4_29
Description of Fenestella (from Wikipedia): The skeleton of Fenestella colonies consists of stiff branches that are interconnected by narrower crossbars (or dissepiments). Between two and eight individuals of the colony inhabit each of the opposing front sides of the approximately rectangular openings between the branches (or fenestule) in one row, and the void they left when they died can be recognized as two rows of small rimmed pores (or apertures) on the front of each branch. In well-preserved specimens these are closed by centrally perforated lids. In Fenestella, the front of the branches may carry small nodes in a row in the middle. Branches split (or bifurcate) from time to time giving the colonies a fan-shaped appearance . . . Compared to other fenestellids with two rows of apertures, Fenestella is relatively fine, with large apertures and wide dissepiments. The distance between apertures in Fenestella remains the same as colonies grow and individuals (or zooids) will have had equal size lophophores.