Pontalun Quarry (St. Bride's Island) (Jurassic to of the United Kingdom)

Also known as Lithalun Quarry, SS 898 765, SS 898765, St. Brides

Where: Wales, United Kingdom (51.5° N, 3.6° W: paleocoordinates 37.7° N, 1.8° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Hettangian to Hettangian (201.3 - 190.8 Ma)

• Fossils come from several fissure systems within the Pontalun Quarry. Fissure fills in Late Carboniferous (Dinantian) limestone. Deposits resulting from Liassic transgression over Carboniferous limestones. Kermack, Mussett, and Rigney (1981) note that a Lower Sinemurian age for the Welsh fissures is supported by evidence in David Pacey's (1978) thesis, which is apparently as yet unpublished.

• group of beds-level stratigraphic resolution

Environment/lithology: fissure fill; limestone and hematitic, gray, green, red, yellow marl

• Fissures in limestone filled with silt, acting as traps for small animals. Localities lie on a small limestone plateau that formed an island (Robinson, 1971) or archipelago in Jurassic times. Triassic to Jurassic subsidence and a transgression by Tethys Ocean gradually resulted in inundation by Early Jurassic (Sinemurian). Such fissure fills formed in open joints in the limestone and are from 0.3 to 1 m wide. Pontalun Quarry contains many tons of matrix.
• The matrix filling of the fissures ranges from soft clay to hard marl and often is rich in hematite grains. Matrix color varies from red to yellow, green and gray, and the bone can be white to dark gray and brown. Typically bone is white and matrix is red. Plant fossils are often preserved as charcoal (fusain) in gray matrix (also in yellow and red). "The best specimens of Morganucodon from Pontalun quarry come from a soft red marl, lightly cemented and full of rounded clay and haematite pellets (Kermack et al. 1973, Table 2, fissure system 2).

Size classes: mesofossils, microfossils

Preservation: charcoalification

Collected by Kermack, Kermack & Mussett in 1954-1968; reposited in the BMNH

Collection methods: quarrying, mechanical,

• University College London (UCL), University Museum of Zoology, Cambridge (UMZC)

•

•Kermack et al. (1973) gives occurrence lists for up to 4 specific fissure systems at Pontalun, but prior and subsequent literature does not typically differentiate fissure systems. Morganucodon teeth are much more common than Kuehneotherium in all St. Bride's quarries (and their fissures), except in Pontalun Fissure I, a "single pocket" containing 5 Morganucodon teeth and 14 Kuehneotherium dental elements from which the type of Kuehneotherium praecursoris was described by Kermack, Kermack, and Mussett 1968 (Evans and Kermack 1994: 275). Collection 46118 represents the whole Pontalun Quarry and all of the fissures mentioned by Kermack et al. (1973).

Primary reference: D. M. Kermack, K. A. Kermack, and F. Mussett. 1968. The Welsh pantothere Kuehneotherium praecursoris. Zoological Journal of the Linnean Society 47(312):407-423 [R. Whatley/R. Whatley/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 46118: authorized by Robin Whatley, entered by Robin Whatley on 03.01.2005, edited by Richard Butler

Creative Commons license: CC BY (attribution)

Taxonomic list

• The type (M. 19165) of Kuehneotherium praecursoris Kermack, Kermack, and Musset 1968 was previously figured and described by Kermack et al. (1965), but not named.

•

•Two taxa of archosaurs (other than the pterosaur) are present at Pontalun (Fraser 1989).

Show authors, comments, and common names
Reptilia
 Archosauria -
Archosauria indet.4
Archosauria indet.4 Cope 1869 archosaur
Tooth, NHMUK R.8178
 Pterosauria - Rhamphorhynchidae
cf. Rhamphorhynchidae indet.3
cf. Rhamphorhynchidae indet.3 Seeley 1870 pterosaur
UMZC T 1315; May be related to Dorygnathus from Liassic of Holzmaden.
 Loricata -
? Crocodylomorpha indet.3
? Crocodylomorpha indet.3 Hay 1930 crocodilian
Teeth
 Rhynchocephalia -
Gephyrosaurus bridensis n. gen. n. sp.1
Gephyrosaurus bridensis n. gen. n. sp.1 Evans 1980 rhynchocephalian
Osteichthyes
 Morganucodonta - Morganucodontidae
Morganucodon watsoni2
Morganucodon watsoni2 Kuehne 1949 mammaliaform
Five teeth (one upper molar and four lower molars)
 Therapsida - Kuehneotheriidae
Kuehneotherium praecursoris n. gen. n. sp.
Kuehneotherium praecursoris n. gen. n. sp. Kermack et al. 1968 mammaliaform
NHMUK (formerly BMNH) M.19165 (holotype), M.19155, C.853, C.855, C.857-866
Equisetopsida
 Pinidae - Pinidae
Hirmeriella muensteri4
Hirmeriella muensteri4 Schenk 1867
1Evans 1980; 2Evans and Kermack 1994; 3Fraser 1989; 4Kermack et al. 1973