Heddleichthys - a new tristichopterid genus from the Dura Den Formation, Midland Valley, Scotland (Famennian, Late Devonian)
2009 (English)In: Acta Zoologica (Stockholm), ISSN 0001-7272, E-ISSN 1463-6395, Vol. 90, no Suppl. 1, 273-284 p.Article in journal (Refereed) Published
A new tristichopterid genus, Heddleichthys, from the Famennian of Scotland is described based on material previously assigned to a number of different genera, including Glyptopomus, Gyroptychius and Eusthenopteron. The validity of the new genus is established by a discussion of the reasons for the invalidity of the previous assignments. Heddleichthys is characterized by a combination of derived and primitive tristichopterid features. Derived features include the presence of symphyseal dentary fangs and premaxillary pseudofangs, a diamond-shaped symmetric caudal fin, a low posterodorsal expansion of the maxilla, and a posteriorly positioned kite-shaped pineal series. Primitive features include a postorbital and jugal contribution to the orbital margin and a parasphenoid with a ventral keel. External dermal bones are rather poorly preserved in the referred material, with few easily discernible sutures. The holotype specimen, a three-dimensionally preserved skull, was scanned by computed tomography to reveal well-preserved internal dermal bones, including entopterygoids, vomers and parasphenoid. There is no preserved endoskeletal material. As the first representative of derived tristichopterids described from Britain, Heddleichthys lends support to the idea that faunal dispersion between Gondwana and Laurussia in the Late Devonian was widespread. Derived tristichopterids have been described from all continents except South America. In contrast, the basal tristichopterids Eusthenopteron and Tristichopterus are still only described from Laurussia.
Place, publisher, year, edition, pages
2009. Vol. 90, no Suppl. 1, 273-284 p.
Heddleichthys, Dura Den, Tristichopteridae, Famennian, Late Devonian
IdentifiersURN: urn:nbn:se:uu:diva-97002DOI: 10.1111/j.1463-6395.2008.00376.xISI: 000266242000023OAI: oai:DiVA.org:uu-97002DiVA: diva2:171765