Search results for "Lochkovian"
showing 4 items of 4 documents
The middle and upper Lochkovian (Lower Devonian) conodont successions in key peri-Gondwana localities (Spanish Central Pyrenees and Prague Synform) a…
2015
Detailed correlation, based on conodont sequences, between middle and upper Lochkovian carbonate successions from two key peri-Gondwanan regions, the Spanish Central Pyrenees and the Prague Synform, is attained for the first time. This correlation facilitates the definition of tie points for further multidisciplinary studies that seek to establish high-resolution temporal subdivision and global correlation. Some intervals have a precision of less than 0.5 Ma, which is significantly greater than in previous studies. The estimated elapsed time considered herein is about 3.2 Ma and is subdivided into five major zones of global scope: transitanstrigonicus, trigonicus-kutscheri, kutscheri-pandor…
LOCHKOVIAN TO PRAGIAN (LOWER DEVONIAN) NERITIC OSTRACODES FROM NIGÜELLA (ZARAGOZA, IBERIAN CHAINS, NE SPAIN)
2021
Lochkovian and Pragian ostracodes from the area of Niguella (Iberian Chains), which is a key area for supra-regional correlation in the Early Devonian, are described for the first time. 12 ostracode taxa from the sections Ni4 and Ni2 could be identified. The silicified ostracodes of Eifelian Ecotype are low in biodiversity, have few individuals, and are comparatively poorly preserved. Characteristic taxa of the Devonian occur. Thus, the faunas show general relations to most European Early Devonian ostracode faunas. Closer relations exist to the Eastern Guadarrama. Polyzygia kroemmelbeini LeFevre & Weyant, 1967 and P. grekoffi Weyant, 1980 are found in the basal Pragian for the first time. B…
A NEW EARLY DEVONIAN THELODONT FROM CELTIBERIA (SPAIN), WITH A REVISION OF SPANISH THELODONTS
2006
: A revision of thelodont scales from the Lower Devonian of the Iberian Chains enables their grouping into two taxa: Turinia pagei and T. nachoi sp. nov. These taxa are clearly distinguishable by morphological and histological features; they also have a different stratigraphic range (T. pagei is restricted to Lochkovian strata, whereas T. nachoi sp. nov. occurs within lower–middle Pragian rocks). The new species is represented by head, transitional (cephalopectoral) and trunk scales.
Enameloid microstructure in the oldest known chondrichthyan teeth
2009
Botella, H., Donoghue, P.C.J and Martinez-Perez, C. 2009. The enameloid microstructure of the oldest known chondrichthyan teeth. — Acta Zoologica (Stockholm) 90 (Suppl. 1): 103‐108 Previous studies on tooth enameloid microstructure in several chondrichthyan taxa spanning the phylogeny of the group provided support for the homology of chondrichthyan tooth enameloid. This hypothesis requires that a single crystallite enameloid (SCE) monolayer must be present in the teeth of the most primitive chondrichthyan. However, the dental microstructure of the earliest sharks has yet to be investigated. We have studied the tooth enameloid microstructure of the two oldest tooth-bearing shark species curr…