Stratigraphic and temporal context and faunal diversity of Permian-Jurassic continental tetrapod assemblages from the Fundy rift basin, eastern Canada

Abstract

<p style="margin: 1em 0px; line-height: 200%; text-indent: 0.5in;"><span style="font-family: 'Minion Pro','serif'; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-CA;"><span style="font-size: medium;">The Fundy basin in Nova Scotia and New Brunswick is the largest exposed rift basin of the Newark Supergroup and also extends beneath the Bay of Fundy. Its strata can be divided into four tectonostratigraphic sequences (TS). TS I is represented by the probably Permian Honeycomb Point Formation and possibly the Lepreau Formation. TS II includes the Wolfville Formation with the probably Middle Triassic Economy Member and the early Late Triassic Evangeline Member. These members have yielded markedly different assemblages of continental tetrapods. TS III comprises most of the Blomidon Formation, which is Norian to Rhaetian in age. The Blomidon Formation has yielded few skeletal remains of tetrapods to date but many tetrapod tracks. TS IV includes the late Rhaetian top of the Blomidon Formation and the McCoy Brook Formation, which overlies the North Mountain Basalt and is latest Rhaetian and earliest Jurassic (Hettangian) in age. The McCoy Brook Formation has yielded a diversity of continental tetrapods and lacks any of the characteristic Late Triassic forms. Recent work has correlated the Global Boundary Stratotype Section and Point (GSSP) for the base of the Jurassic (Hettangian) to a level well above the North Mountain Basalt. Thus most of the tetrapod fossils from the McCoy Brook Formation are latest Rhaetian in age, but the higher horizon with skeletal remains of sauropodomorph dinosaurs may be earliest Hettangian in age. The Fundy basin preserves the only known, stratigraphically tightly constrained record of the profound biotic changes in continental ecosystems across the Triassic-Jurassic transition.</span></span></p>

Supradapedon revisited: geological explorations in the Triassic of southern Tanzania

“…A clade formed by Hyperodapedon sanjuanensis and the Nova Scotia (Baird, 1963; Sues & Olsen, 2015) plus Wyoming (Lucas, Heckert & Hotton III, 2002) forms has also been recovered (Fig. 10), matching previous suggestions in the literature (Chatterjee, 1980; Lucas, Heckert & Hotton III, 2002; Mukherjee & Ray, 2014).…”

“…Also, this generalization can be hinted for units with a less abundant fossil record, but with members of the “ Hyperodapedon clade” as one of the recognized taxa, such as the Popo Agie and Pebbly Arkose formations, the Evangeline Member of the Wolfville Formation, as well as the here discussed (see above) Mahogo Formation. Indeed, as for the best known North American strata, a recent and comprehensive review of the Fundy Rift Basin (Sues & Olsen, 2015) gathered evidence of an agreeing late Carnian age for the Evangeline Member of the Wolfville Formation, which yielded the Nova Scotia form, and a similar age has also been hinted for the Popo Agie Formation (Hartman, Lovelace & Stocker, 2015), which yielded the Wyoming form. Radiosisotpic dates are still missing for the Tiki, lower part of the Maleri, and Lossiemouth Sandstone formations, but these could test the validity of Hyperodapedon as a late Carnian (Tuvalian) index fossil.…”

“…Dotted lines indicate reconstructed parts. F. spenceri represented by EXEMS 60/1985.292; I. genovefae by FMNH-9-8-98-525 (from Whatley, 2005); S. stockleyi by SAM-PK-11705; H. gordoni by NUDG A (from Benton, 1983); H. tikiensis by IITKGPR51, (from Mukherjee & Ray, 2014); H. huenei by UFRGS PV-0123T; T. sulcognathus by UFRGS PV-0298T; H. huxleyi by ISIR 17 (from Chatterjee, 1974); H. mariensis by UFRGS PV-0408T; Zimbabwe form by BP Z53/3; H. sanjuanensis by MCP 1693; Wyoming form by USNM 494329 (from Lucas, Heckert & Hotton III, 2002); Nova Scotia by NSM 012GF032.026 (from Sues & Olsen, 2015). …”

“…in some hyperodapedontines, as epitomized by the condition seen in Hyperodapedon sanjuanensis (Azevedo, 1984) and, less clearly because of the scarcity of material, the North American forms (Lucas, Heckert & Hotton III, 2002; Sues & Olsen, 2015). This was previously believed to represent the sole general trend along Hyperodapedontinae tooth evolution (Langer & Schultz, 2000b), starting with a plesiomorphic condition for hyperodapedontines supposedly close to that of Teyumbaita sulcognathus , where the medial structures of the jaw are more developed then the lateral ones.…”

First record of the tritylodontid cynodont Oligokyphus and cynodont postcranial bones from the McCoy Brook Formation of Nova Scotia, Canada

“…Furthermore, the skull of the sphenodontian reptile Clevosaurus bairdi from Wasson Bluff (Sues et al 1994) is virtually indistinguishable from that identified as Clevosaurus sp. from an unidentified locality in the "Stormberg Group" of southern Africa (Sues and Reisz 1995) and that of Clevosaurus brasiliensis from the Caturrita Formation (Late Triassic: Norian) of Brazil (Bonaparte and Sues 2006). First described from Late Triassic fissure-fillings in southwestern England (Fraser 1988), Clevosaurus has also been reported from the Lower Jurassic Lower Lufeng Formation of Yunnan, China (Jones 2006) and Early Jurassic fissure-fillings in Wales (Säilä 2005).…”