Australian Museum Journal Early Devonian conodonts from the Kuan Tung Formation, Thailand: systematics and biogeographic considerations
- Shortform:
- Long and Burrett, 1989, Rec. Aust. Mus. 41(2): 121–133
- Author(s):
- Long, John A.; Burrett, C. F.
- Year published:
- 1989
- Title:
- Early Devonian conodonts from the Kuan Tung Formation, Thailand: systematics and biogeographic considerations
- Serial title:
- Records of the Australian Museum
- Volume:
- 41
- Issue:
- 2
- Start page:
- 121
- End page:
- 133
- DOI:
- 10.3853/j.0067-1975.41.1989.140
- Language:
- English
- Date published:
- 22 September 1989
- Cover date:
- 22 September 1989
- ISSN:
- 0067-1975
- CODEN:
- RAUMAJ
- Publisher:
- The Australian Museum
- Place published:
- Sydney, Australia
- Subjects:
- DEVONIAN: EARLY; CONODONTS
- Digitized:
- 20 September 2007
- Available online:
- 04 March 2009
- Reference number:
- 140
- EndNote package:
- EndNote file
- Title page:
- Title page (87kb PDF)
- Complete work:
- Complete work (2952kb PDF)
Abstract
A small conodont assemblage, obtained from a limestone marking the boundary between the middle and upper units of the Kuan Tung Formation, Satun Province, South Thailand, contains inter alia Pandorinellina steinhornensis steinhornensis, Polygnathus labiosus mawsonae n.subsp., and Pseudooneotodus kuangtungensis n.sp., indicating an Emsian age (perbonus-serotinus Zones). Studies on ontogenetic variation in Pa elements of Polygnathus labiosus mawsonae n.subsp. show that smaller Pa elements have fewer transverse ridges on the posterior third of the platform, more distinct marginal denticulation on the platform and a proportionately smaller basal cavity. The basal cavity lips may break off in mature specimens; this gives an appearance of a small basal cavity. The distribution of P. labiosus, P. pseudoserotinus, P. perbonus and Pseudooneotodus kuantungensis n.sp., in the Shan-Thai and South China Terranes, together with supporting evidence from thelodontid and placoderm fishes, suggests that these terranes were in close proximity to the eastern margin of Gondwana at the end of the Early Devonian.