Post−extinction survivor fauna from the lowermost Famennian of eastern North America (original) (raw)

The Cleveland Shale fauna and the Devonian-Mississippian transition in Ohio and Pennsylvania (U.S.A

Ichthyolith Issues Special Publications 13, 2017

The Famennian fish fauna from the Cleveland Shale Member (Ohio Shale Formation) represents a 160-year collection effort starting in the mid-19th Century and continuing today. Three periods of increased research include 1857-1909 with such notable names as Newberry, Claypole, Dean, and Hussakof. This was followed in the 1930-1947 period with the work of Dunkle and Bungart. Since 1964 there has been a steadily increasing interest in the Cleveland Shale fauna. Hlavin (1976) completed the first comprehensive review of the fauna and noted 40 vertebrate taxa. This number has grown to 66 taxa (Carr & Jackson, 2008), more than double the next-most speciose Famennian fauna (32 species, Tafilalt, Morocco; Lelièvre, 2003), and our knowledge of the Cleveland Shale fauna continues to grow. This growth includes a new genus and species of selenosteid arthrodire, other new species in the shoreward laterally-equivalent Chagrin Shale Member (Ohio Shale Formation), and the preparation of new material for taxa that are only know from limited or incomplete specimens. The discovery of placoderm egg cases in the Cleveland Shale (Carr, 2010a) demonstrates the equal antiquity of oviparity and viviparity among the basal gnathostomes. The pelagic nature of the large arthrodires (Carr, 2010b) associated with these egg cases suggests the possibility of arthrodiran hatcheries in the eastward shallower parts of the Appalachian Basin. An interesting note regarding the diversity of the Cleveland Shale fauna is the lack of any analysis of microvertebrates, although bone beds and lag deposits have been identified in the field. The Cleveland Shale was considered at one time to represent the latest Devonian with the overlying Bedford Shale and Berea Sandstone Formations representing the earliest Mississippian (e.g., Lewis, 1988). This entire sequence, found in the Cleveland, Ohio area and NW Pennsylvania, is now considered to represent the latest Devonian (Brezinski et al., 2010; Baird et al., 2011; Baird, 2013) and is equivalent to the Hangenberg shales and sandstones of the European Hangenberg Biocrisis (Kaiser et al., 2016). Associated with the biocrisis is an episode of end-Devonian glaciation. This is documented in the eastern Appalachian Basin by a succession of glacigenic tillites (Brezinski et al., 2010). In Kentucky, a 3-ton granitic dropstone is embedded within the Cleveland Shale (Lierman et al., 2009) suggesting ice rafting from eastern glaciated regions. The correlation between the Ohio and NW Pennsylvania sequences with those in the glaciated regions of the eastern Appalachian Basin remains unclear. However, the presence of a series of unit-boundary bone beds and bone-containing lag deposits within the Cleveland Shale offer the opportunity to correlate these units, to tie the Appalachian events to those of Europe, and to document the pattern of extinction for the vertebrates in Cleveland Shale fauna. Sallan & Coates (2010) report both a loss of diversity and a complete restructuring of the vertebrate worldwide communities associated with the Hangenberg Biocrisis; however, they note a lack of

Middle and Late Devonian vertebrates of the western Old Red Sandstone Continent

COURIER- …, 2000

"Little has been done up to now to use vertebrlj.tes to develop biostratigraphic correlation in the Middle and Late Devonian of the western Old Red Sandstone Continent. This is mostly due to the poor documentation of the fauna and the difficulty of dating that which is known. In western North America Middle Devonian vertebrates are more cosmopolitan that those of the Early Devonian which should make them more useful in biostratigraphy; however, a combination of lack of precision in identification and apparent long temporal ranges currently limits their utility. Associated invertebrates allow the Yahatinda Fonnation (Alberta) and the Denay Limestone (Nevada) to be placed in the Givetian while the upper part of the Grassy Flat Member of the Water Canyon Foqnation (Utah) and the Spring Mountain Channel (Idaho) are Eifelian. As these localities typically contain faunas that include tuberculate pteraspidids, Asterolepis, Holonema, and osteolepids there is insufficient precision as yet to separate them based on the vertebrates. The Late Devonian is poorly represented by vertebrate faunas other than the reports from the Martin Fonnation of northern Arizona where a Frasnian fauna of ptyctodonts and arthrodires can be correlated with the Temple Butte Formation northwards. The Elbert, Parting, and Darby formations of Colorado are Famennian in age and contain similar faunas that include Bothriolepis coloradensis, large arthrodires, dipnoans, and osteolepids. In the mid-continent vertebrates are found in the Michigan, Iowa, and Illinois basins. Large collections of chondrichthyans and arthrodires have been made from the Famennian Cleveland Shale in particular and collections are being developed in the correlative Antrim Shale, however, the potential for biostratigraphic correlation has yet to be tapped in this area. In the eastern part of the continent the Catskill delta complex of the Appalachian Basin rcrpresents sediments of Famennian age. The lower fauna contains Bothriolepis and Holoptychius commonly together with the rhizodontiform Sauripterus, while the upper fauna contains a more diverse fauna of chondrichthyans and arthrodires together with the osteolepifonns Eusthenodon and Hyneria, the dipnoan Soederberghia, and the tetrapod Hynerpeton. To the north the Escuminac Formation of the Appalachian basin is interpreted as a coastal marine deposit of estuarine origin and is Frasnian in age. Despite having a diverse fauna of agnathans, arthrodires, acanthodians, actinopterygians, and sarcopterygians only three species have been identified elsewhere, Bothriolepis canadensis (from Belgium and Turkey), and Cheirolepis canadensis and Eusthenopteronfoordi (from Nevada). However, in each case the identifications are doubtful suggesting that this is another endemic fauna with little applicability to correlation with other faunas . In the Okse Bay Formation from Ihe Frasnian of Ellesmere Island psammosleids. althrodires and antiarchs. and the rhipidistians Glyptoleph. Holoptychills. and Osteolepis occur. Although the Middle and Late Devonian was a time in which much of the western Old Red Sandstone Conlinenl was divided into separate depositional basins with endemic faunas it does appear that a more detailed analysis of the faunas will yield the data needed for biostratigraphic correlation as is already being shown in western Nolth America."

Paleoecological Analysis of a Late Devonian Catskill formation

The Red Hill site located along a road cut near Hyner in Clinton County, Pennsylvania, represents a floodplain ecosystem during the late Famennian Stage of the Upper Devonian Period. Fossil vertebrates from the Red Hill site include those of sarcopterygian fish, placoderms, acanthodians, actinopterygian fish, freshwater sharks, and early tetrapods. Vertebrate microfossils are often used to assess the paleoecology of extinct ecosystems. Differences in species richness in similar geological sediments can indicate differences in the paleoecology between locations. Fossils were collected from two distinct strata: an oxidized stratum representing the sediments from the main river channel margins and a reduced stratum representing sediment from highly vegetated floodplain ponds. Four quarries were excavated at the Red Hill site with two quarries in each strata. Vertebrate fossils were identified and counted from each quarry. A total of 293 vertebrate fossils were recorded. These fossils included teeth and scales of Hyneria lindae, dermal bony plates of Groenlandaspid placoderms, scales of Megalichtyid sarcopterygian fish, Gyracanthus sp. spines, teeth of Ageleodus pectinatus (freshwater shark), and body impressions of Limnomis delaneyi. A total of 17 H. lindae scales, 3 H. lindae teeth, 12 placoderm plates, 5 megalichthyid scales, 2 Gyracanthus spines, and 2 Limnomis partials were found in the reduced strata. A total of 128 H. lindae scales, 33 H. lindae teeth, 72 placoderm plates, 37 megalichthyid scales, 11 Gyracanthus spines, and 10 Ageleodus pectinatus teeth were collected from the oxidized strata. From these data, I concluded that the main river channel habitats contain higher densities of vertebrates than the still water ponded environments. My findings also possibly indicate that the flowing water and ponded water types of habitats preserved at Red Hill supported different types of vertebrate communities.