Norman M. Savage

Bio: Norman M. Savage is an academic researcher from University of Oregon. The author has contributed to research in topics: Devonian & Late Devonian extinction. The author has an hindex of 11, co-authored 33 publications receiving 296 citations.

Conodonts of Caradocian (Late Ordovician) age from the Cliefden Caves Limestone, southeastern Australia

Abstract: New species of Aphelognathus, Belodina, Taoqupognathus, and Yaoxianognathus have been identified in the Late Ordovician Cliefden Caves Limestone Group in central-western New South Wales, Australia. Of the Aphelognathus species, Aphelognathus percivali n. sp. and A. webbyi n. sp. occur in the basal Gleesons Limestone Member and A. packhami n. sp. and A. stevensi n. sp. occur 30 m higher in the Wyoming Limestone Member. It seems likely from the similarity of several of the elements that A. packhami is closely related to A. percivali, and A. stevensi to A. webbyi. Yaoxianognathus wrighti n. sp. occurs in the Gleesons Limestone Member but not in the Wyoming Limestone Member. Belodina confluens, Belodina hillae n. sp., Belodina n. sp., Panderodus gracilis, Taoqupognathus philipi n. sp., and Phragmodus? tunguskaensis occur at both horizons. The conodonts suggest a middle to late Caradocian (mid-Shermanian to mid-Edenian) age for the lowest part of the Cliefden Caves Limestone. The occurrence in southeastern Australia of the forms Taoqupognathus, Yaoxianognathus, and Phragmodus? tunguskaensis suggest affinities to coeval faunas in China and eastern Siberia. The four new species of Aphelognathus are distinct from known species in the Late Ordovician of North America and Europe but they may help characterize a paleobiogeographic region that includes eastern Australia and southeast Asia.

Early to Middle Pennsylvanian conodonts from the Klawak Formation and the Ladrones Limestone, southeastern Alaska

Abstract: Nine genera and 14 species of conodonts were recovered from 54 productive horizons in the Klawak Formation and the Ladrones Limestone, southeastern Alaska. All of the conodonts are assigned to known genera, but two new species, Taphrognathus alaskensis n. sp. and Idio- gnathoides pacificus n. sp., are present. The lower part of the Klawak Formation is considered to range from middle Morrowan to middle Atokan age, mostly on the basis of the occurrence of Idiognathoides noduliferus and Idiognathodus delicatus. The remainder of the Klawak Formation appears to range from middle Atokan to late Desmoinesian age but with only the middle and late Desmoinesian part exposed above the sea. This interval is characterized in our faunas by the occurrence of Idiognathodus excelsus, Idiognathodus delicatus and Neognathodus medexultimus. The Ladrones Limestone is considered to range from middle Morrowan to middle Atokan in age. An open-marine, mainly quiet-water environment, fluctuating with anoxic restricted conditions, is indicated for the Klawak Formation by the conodonts and the thin-section textures. A farther off-shore, reef environment is indicated for the Ladrones Limestone. The faunas are relatively cosmopolitan. What affinity they do have appears to be mainly with other North American faunas.

Silurian (Llandovery–Wenlock) conodonts from the base of the Heceta Limestone, southeastern Alaska

Abstract: The base of the Heceta Limestone, exposed on Cap Island in southeastern Alaska, appears to lie close to the top of the celloni Zone. The succeeding 8 m of strata lies within the amorphognathoides Z...

Late devonian (frasnian and famennian) conodonts from the wadleigh limestone, southeastern alaska

Abstract: Conodont faunas from the upper part of the Wadleigh Limestone, Alexander terrane, southeastern Alaska, are of Frasnian to early Famennian age and include the new taxa Polygnathus aspelundi nanus n. subsp., Polygnathus decorosus dutroi n. subsp., Polygnathus elegantulus sparus n. subsp., Polygnathus gracilis n. subsp. A, Polygnathus n. sp. A, Palmatolepis subrecta youngquisti n. subsp., and Icriodus subterminus uyenoi n. subsp. Four distinct age-determined faunal assemblages are recognized. The lowest is assigned to the Lower Palmatolepis rhenana Zone (the chronozones of Ziegler and Sandberg, 1990, are treated herein as time-rock equivalent assemblage zones). The next is exposed on three small islands just south of Wadleigh Island and is correlated with part of the Lower to Upper Palmatolepis rhenana Zones. The third assemblage, on the eastern side of Wadleigh Island from close to the top of the section, is correlated with part of the Palmatolepis linguiformis Zone. Nearby and overlying this is the fourth assemblage, which is correlated with part of the Lower Palmatolepis triangularis Zone and thus appears to be within the lower Famennian. These Wadleigh Limestone conodont faunas have affinities with faunas from equivalent horizons of the cratonic regions of the Northwest Territories and Alberta in Western Canada and to other faunas globally. The more provincial conodont taxa lend weak but positive support to brachiopod faunal evidence that places the Alexander terrane close to the North American craton during the Late Devonian.

Middle Devonian (Eifelian) conodonts of the genus Polygnathus from the Wadleigh Limestone, southeastern Alaska

Abstract: Conodonts from the lowest known horizon of the Wadleigh Limestone, southeastern Alaska, include Polygnathus trigonicus Bischoff and Ziegler, P angustipennatus Bischoff and Ziegler, P angusticosta

Early Silurian oceanic episodes and events

Abstract: Biotic cycles in the early Silurian correlate broadly with postulated sea-level changes, but are better explained by a model that involves episodic changes in oceanic state. Primo episodes were characterized by cool high-latitude climates, cold oceanic bottom waters, and high nutrient supply which supported abundant and diverse planktonic communities. Secundo episodes were characterized by warmer high-latitude climates, salinity-dense oceanic bottom waters, low diversity planktonic communities, and carbonate formation in shallow waters. Extinction events occurred between primo and secundo episodes, with stepwise extinctions of taxa reflecting fluctuating conditions during the transition period. The pattern of turnover shown by conodont faunas, together with sedimentological information and data from other fossil groups, permit the identification of two cycles in the Llandovery to earliest Wenlock interval. The episodes and events within these cycles are named: the Spirodden Secundo episode, the Jong Primo episode, the Sandvika event, the Malmoykalven Secundo episode, the Snipklint Primo episode, and the Ireviken event.

Biology of living brachiopods

Abstract: Publisher Summary This chapter describes the biology of living brachiopods. The Brachiopoda are significant components of the early Cambrian marine Faunas and are therefore one of the few phyla to be represented of the Phanerozoic era, which extends from the first widespread appearance of organisms with mineralized skeletons until modern times. The objective of chapter review is to chronicle some of the important biological work conducted over the past 25 years and to present an overview of current trends in brachiopod biology. Moreover, many of the recent studies of living brachiopods owe their motivation to a desire to improve palaeontological interpretation of the group. The scaling patterns of brachiopod tissue and other components in relation to total size and their morphological architecture show significant differences from the bivalves and may impose important constraints. Moreover, a general impression of many living articulate brachiopods is of a relatively small organism, in terms of organic tissues, inhabiting a relatively large space, defined by the shell. Brachiopods approximate spherical shapes, as much as their growth patterns and articulation systems allow. This chapter concludes that the brachiopod biomineralization system is ideally suited for the investigation of the interaction between the organic and the inorganic phases during shell growth.

Geologic framework, tectonic evolution, and displacement history of the Alexander Terrane

Abstract: The Alexander terrane consists of upper Proterozoic(?)-Cambrian through Middle(?) Jurassic rocks that underlie much of southeastern (SE) Alaska and parts of eastern Alaska, western British Columbia, and southwestern Yukon Territory. A variety of geologic, paleomagnetic, and paleontologic evidence indicates that these rocks have been displaced considerable distances from their sites of origin and were not accreted to western North America until Late Cretaceous-early Tertiary time. Our geologic and U-Pb geochronologic studies in southern SE Alaska and the work of others to the north indicate that the terrane evolved through three distinct tectonic phases. During the initial phase, from late Proterozoic(?)-Cambrian through Early Devonian time, the terrane probably evolved along a convergent plate margin. Arc-type(?) volcanism and plutonism occurred during late Proterozoic(?)-Cambrian and Ordovician-Early Silurian time, with orogenic events during the Middle Cambrian-Early Ordovician (Wales orogeny) and the middle Silurian-earliest Devonian (Klakas orogeny). The second phase is marked by Middle Devonian through Lower Permian strata which accumulated in tectonically stable marine environments. Devonian and Lower Permian volcanic rocks and upper Pennsylvanian-Lower Permian syenitic to dioritic intrusive bodies occur locally but do not appear to represent major magmatic systems. The third phase is marked by Triassic volcanic and sedimentary rocks which are interpreted to have formed in a rift environment. Previous syntheses of the displacement history of the terrane emphasized apparent similarities with rocks in the Sierra-Klamath region and suggested that the Alexander terrane evolved in proximity to the California continental margin during Paleozoic time. Our studies indicate, however, that the geologic record of the Alexander terrane is quite different from that in the Sierra-Klamath region, and we conclude that the two regions were not closely associated during Paleozoic time. The available geologic, paleomagnetic, and paleontologic data are more consistent with a scenario involving (1) early Paleozoic origin and evolution of the Alexander terrane along the paleo-Pacific margin of Gondwana, (2) rifting from this margin during Devonian time, (3) late Paleozoic migration across the paleo-Pacific basin in low southerly paleolatitudes, (4) residence in proximity to the paleo-Pacific margin of South America during latest Paleozoic(?)-Triassic time, and (5) Late Permian(?)-Triassic rifting followed by northward displacement along the eastern margin of the Pacific basin.

A new latest Telychian, Sheinwoodian and Early Homerian (Early Silurian) Standard Conodont Zonation

Abstract: The new standard conodont zonation includes, in succession from below: Lower Ps bicornis Zone, Upper Ps bicornis Zone, Lower P procerus Zone, Upper P procerus Zone, Lower K ranuliformis Zone, Upper K ranuliformis Zone, 0 s rhenana Zone, Lower K walliseri Zone, Middle K walliseri Zone, K patula Zone, uppermost K walliseri range, post K walliseri interregnum, K o ortus Zone and 0 s sagitta Zone Lower boundaries for each zone are defined or redefined A less detailed biostratigraphic nomenclature at the superzone level is suggested for use where collections are inadequate: The Pterospathodus Zonal group, the Upper Pterospathodus Zonal group, the P amorphognathoides Zonal group, the Ps bicornis Superzone, the P procerus Superzone, the K ranuliformis Superzone, the O s rhenana Superzone, the K walliseri Zonal group, the Upper K walliseri Superzone and the K o ortus Superzone These partly overlap and can be used according to the taxa present The proposed zonation is applied to most known conodont sequences The taxonomic concept of the taxa used is discussed; new taxa include Nudibelodina sensitiva, Ozarkodina paraconfluens and O martinssoni The species name Ozarkodina ortus is a senior synonym of Kockelella absidata