R. E. H. Reid

Bathymetric distributions of Calcarea and Hexactinellida in the present and the past

Sponge faunas, depth zoning, significance of modern distributions for assessment of past depths, problems of overlapping depth ranges, differences in modern and fossil forms, temperature influence, independent evidence of bathymetry from algae-corals

Primary bone and dinosaurian physiology

Primary compact bone is ignored in some recent discussions of claims that dinosaurs were endotherms, but forms the basis of one of the arguments from bone, and part of the basis of another. This paper explains its histology and discusses its possible significance. In dinosaurs the primary compact bone was commonly fibre-lamellar bone, resembling bone seen in many large mammals, and implying a capacity to sustain rapid growth to large sizes. This probably indicates some physiological difference between dinosaurs and modern types of reptiles; but similar bone is present in early therapsids, which were probably not endotherms, and bone with typical reptilian ‘growth rings’ was sometimes formed. Endothermy is also unlikely in most kinds of dinosaurs, if its evolution requires a trend to small sizes; but perhaps they were ‘failed endotherms’.

Hexactinellid faunas in the Chalk of England and Ireland

The Chalk of England contains three main hexactinellid faunas, of lower Cenomanian, middle and upper Turonian, and lower Senonian to Maestrichtian age respectively. The third is also represented in Ireland. A number of minor faunal changes can also be recognized. The three main faunas have little in common, and their relationship is not evolutionary; the changes appear to be due to migrations. By analogy with modern forms, this is likely to reflect changes in the pattern of current circulation in the upper Cretaceous ocean.

Sponges and the Chalk Rock

Chalk Rock lithology suggests shallow-water conditions, but the fauna has been said (Woods, 1897; Jukes-Brown, 1904) to imply a depth between about 100–500 fm. A study of the sponges which are numerous in the Oxfordshire–Hertfordshire area shows that these form a fauna of the sort which is typical of the Chalk as a whole, with Hexactinellida predominant as was pointed out by Woods; this is a fauna of deep-water type by both modern and Cretaceous standards. The depth which these sponges imply need, however, not be much more than 100 fm., and their presence need have no direct bearing on the depth at which erosional features were formed.

Occurrence of Chancelloria Walcott in the Comley limestone

Records and describes spicules of the heteractinellid sponge Chancelloria, found in material etched from the Comley limestone (Cambrian) and the first to be recorded outside of North America.

Hyalostelia Zittel and the Heteractinellida

In a paper on dolomitization of siliceous microfossils by B. K. Holdsworth (for reference, see this Bibliography Vol. 31, No. 8, 14 E67-07193) the sponge Hyalostelia is referred to the Heteractinellida, described as 9an exclusively siliceous group.9 It is here pointed out that Hyalostelia belongs to the Hexactinellida, not the Heteractinellida and that the nature of heteractinellid spicules is actually not known. There is evidence that they may be calcareous.

Pre- Belemnitella Mucronata White Limestone in North-Eastern Antrim

Reports the occurrence in several localities on the Antrim coast of Ireland of a Gonioteuthis zone in the White Limestone (Cretaceous), occurring below the Belemnitella mucronata zone which has been considered to be the first occurrence of belemnites. It is also noted that White Limestone as low as the Marsupites testudinarius zone can be identified in several localities. The Gonioteuthis localities are described. Also considered is the question of the deposition of the White Limestone of M. testudinarius age across the area of the Highland Border ridge and it is presumed that it occurred across the northeastern end.

Age of the Cretaceous basal conglomerate at Murlough bay, County Antrim

The recent find of two specimens of the sponge Rhizopoterion cribrosum suggests a middle or upper Senonian age for the Cretaceous basal conglomerate in the coastal area of Murlough bay, Ireland, whose exact zonal position has previously been unknown.