Netherlands Journal of Geosciences / Geologie en Mijnbouw 82 (3): 225-231 (2003) Oligotrophic oceans and minimalist organisms: collapse of the Maastrichtian marine ecosystem and Paleocene recovery in the Cretaceous-Tertiary sequence of New Jersey W.B. Gallagher1 1 New Jersey State Museum,TRENTON, New Jersey 08625-0530, USA; and Department of Geological Sciences, Rutgers University, PISCATAWAY, New Jersey 08855, USA; "^ •"•" e-mail: [email protected] l^^ I Manuscript received: June 2000; accepted in revised form: October 2001 | G Abstract The inner Atlantic Coastal Plain of New Jersey reveals exposures of fossiliferous Maastrichtian and Danian deposits. Recent fossil discoveries in this interval are here reported, and placed in the context of Cretaceous/Tertiary (K/T) faunal changes. The exposure at the Inversand Pit at Sewell (New Jersey) is the last active marl mine in the region, and stands as an important reference section for the many significant discoveries of vertebrate fossils produced by the marl mining industry at its zenith. Changes in planktonic populations across the K7T boundary are related to Maastrichtian/Danian marine ecosystem commu­ nity reorganisation, by demonstrating changes in abundance of dominant marine invertebrates in successive fossil assem­ blages. Marine invertebrates with non-planktotrophic larval stages were briefly the commonest fossils preserved in the Danian sediments of this region. Late surviving examples of Cretaceous fauna now restricted to the Indo-Pacific region may imply biogeographic changes linked to the R7T mass extinction event. Keywords: Maastrichtian, Danian, K/T boundary, faunal assemblages, New Jersey Introduction sils in North America. At Haddonfield (Camden County), the site of the discovery of Hadrosaurus New Jersey played a prominent role in the early de­ foulkii was an old marl pit that yielded the most com­ velopment of the science of palaeontology in North plete skeleton of a dinosaur known at that time (Lei- America, and although the fossiliferous deposits of dy, 1858). Since then, the marl deposits have yielded the New Jersey Coastal Plain have been studied for numerous specimens to private and professional col­ two centuries, new discoveries and interpretations are lectors. Fossils of Maastrichtian age are found in the still emerging from these classic sections. The inner Monmouth Group, consisting of the Mount Laurel, Coastal Plain of New Jersey is underlain by deposits Navesink, Red Bank and Tinton formations, in as­ of Late Cretaceous and Early Cenozoic age (Fig. 1); cending order (Table 1). Typical Maastrichtian taxa these beds contain an abundant record of life at the include the bivalve genera Exogyra, Pycnodonte, and end of the Mesozoic Era. Some of the most fos­ Agerostrea, belemnite guards (Belemnitella americana), siliferous deposits are the beds of glauconite which the small brachiopod Choristothyris plicata, and shark were widely mined as fertiliser in the nineteenth cen­ teeth of several species [Scapanorhynchus texanus, tury. Squalicorax pristodontus, Cretolamna appendiculata], The greensand marl pits produced many of the ear­ plus scrappy remains of various vertebrates. liest discoveries of dinosaurs and other vertebrate fos­ Recently, Miller et al. (1999) have interpreted the Netherlands Journal of Geosciences / Geologie en Mijnbouw 82(3) 2003 225 Downloaded from https://www.cambridge.org/core. IP address: 170.106.202.8, on 01 Oct 2021 at 20:30:31, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0016774600020813 Table. 1. Stratigraphy of Atlantic Coastal Plain in New Jersey. PERIOD EPOCH GROUP FORMATION Quaternary Pleistocene Cape May Tertiary Pliocene Pensauken Miocene Cohansey Kirkwood Eocene Shark River Manasquan Paleocene Rancocas Vincentown Hornerstown . K/T boundary Cretaceous Late Monmouth Tinton Red Bank Navesink Mount Laurel Matawan Wenonah Marshalltown Englishtown Woodbury Merchantville Magothy Raritan Table 2. Formations, dominant fossils, and reproductive types in the inner Coastal Plain K/T section of New Jersey. Horizon Fossils Reproductive type 75°00 Vincentown bryozoans non-planktotroph Fig. 1. Outcrop belt of Upper Cretaceous-Paleocene sediments in Oleneothyris brachiopod non-planktotroph the Atlantic Coastal Plain of New Jersey; the cross marks the loca­ Hornerstown sponges, brachiopods non-planktotroph tion of the Inversand Pit. MFL oysters, clams planktotroph Navesink oysters planktotroph Mount Laurel-Navesink contact as a sequence Mt Laurel (top) clams planktotroph boundary caused by glacio-eustatic sea level fall, with Marshalltown oysters planktotroph the novel conclusion that continental glaciation was a driving sea level change as far back as the Late Creta­ ceous. Certainly, our taphonomic studies support the Cretaceous multituberculate incisor (Grandstaff et idea of falling sea level in the upper Mount Laurel, al.,2000). and the contact between the two formations is quite The Red Bank and Tinton formations have limited abrupt. Just below the contact, a concentration of fos­ areal extent in Monmouth County before pinching sils comprises abundant fossil vertebrate remains, pri­ out to the southeast. In the southern part of the out­ marily chondrichthyan and mosasaur material, as well crop belt, the Navesink Formation is directly overlain as an invertebrate assemblage dominated by inoce- by the Hornerstown Formation, the bulk of which is ramids and ammonites. The superjacent Navesink Danian in age. Paleocene deposits are combined into Formation is a transgressive unit containing several the Rancocas Group, including the Hornerstown and oyster bed assemblages in its greensand marl. Recent­ Vincentown formations. The Red Bank Formation ly discovered, noteworthy finds in the Monmouth has yielded Maastrichtian fossils, primarily the bi­ Group marl beds of Late Cretaceous age include a valve Cucullaea and shark teeth. The boundary be­ hollow coelurosaurian long bone shaft, the first lung- tween the inner Coastal Plain underlain by Upper fish jaw plate known from the Upper Cretaceous of Cretaceous and Lower Cenozoic strata, and the outer North America (Parris et al., 2001), and a possible Coastal Plain composed of younger Cenozoic sedi- 226 Netherlands Journal of Geosciences / Geologie en Mijnbouw 82(3) 2003 Downloaded from https://www.cambridge.org/core. IP address: 170.106.202.8, on 01 Oct 2021 at 20:30:31, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0016774600020813 Table 3. Faunal list for the Inversand Pit, Mantua Township, Gloucester County, New Jersey. Navesink Formation (Maastrichtian) Basal Hornerstown Formation (MFL) Osteopygis emarginatus Cope Peretresius cf. emarginatus Leidy Porifera Brachiopoda Crocodylia Cliona cretacea Fenton & Fenton Terebratulina atlantica Morton Hyposaurus rogersii Owen Brachiopoda Bivalvia Diplocynodon sp. Choristothyris plicata (Say) Nuculana stephensoni Richards cf. Procaimanoidea sp. Bryozoa Cucullaea vulgaris Morton Bottosaurus harlani Meyer indeterminate encrusting bryozoans Glycymeris mortoni (Conrad) Thoracosaurus neocesariensis (DeKay) Bivalvia Gervilliopsis ensiformis (Conrad) Squamata Cucullaea antrosa Morton Pycnodonte dissimilaris Mosasaurus sp. Cucullaea neglecta Gabb Gryphaeostrea vomer Morton indeterminate mosasaurids Cucullaea vulgaris Morton Veniella conradi Morton Aves Glycymeris mortoni (Conrad) Cardium tenuistriatumWhitfield Telmatornis priscus Marsh Agerostrea nasuta (Morton) Etea delawarensis (Gabb) Paleotringa littoralis Marsh Pycnodonte convexa (Say) Crassatellites vadosus (Morton) Graculavis velox Marsh Gryphaeostrea vomer Morton Panopea decisa Conrad indeterminate birds Exogyra costata Say Lithophaga ripleyana Gabb Trigonia mortoni Whitfield Xylophagella irregularis (Gabb) Crassatellites vadosus (Morton) Gastropoda Middle Hornerstown Formation fossil Liopistha protexta (Conrad) Lunatia halli Gabb assemblage Spondylus (Dianchora) echinata (Morton) Gyrodes abyssinus Morton Pachycardium spillmani (Conrad) Turritella vertebroides Morton Porifera Solemya cf. lineolatus Conrad Anchura abrupta Conrad Peridonella dichotoma Gabb Lithophaga ripleyana Gabb Volutoderma ovata Whitfield Cnidaria Gastropoda Turbinella subconica Gabb Flabellum mortoni Vaughan Lunatia halli Gabb Turbinella parva Gabb Brachiopoda Gyrodes petrosus (Morton) Pyropsis trochiformis (Tuomey) Oleneothyris harlani forma manasquani Turritella cf. vertebroides Morton Acteon cretacea Gabb Stenzel Anchura cf. abrupta Conrad Nautilida Bivalvia Anchura pennata (Morton) Eutrephoceras dekayi (Morton) Cucullaea macrodonta Whitfield Pyrifusus macfarlandiWhitfield Ammonoidea Ostrea glandiformisWhitfie\d Turbinopsis curta Whitfield Baculites sp. Crassatellites cf. littoralis Conrad Volutomorpha ponderosa Whitfield Pachydiscus {Neodesmoceras) sp. Caryatis veta Whitfield Nautilida Sphenodiscus lobatus (Tuomey) Gastropoda Eutrephoceras dekayi Morton Crustacea cf. Volutacorbis sp. Ammonoidea cf. Hoploparia sp. Nautilida Baculites ovatus Say Chondrichthyes cf. Aturia sp. Discoscaphites conradi (Morton) Edaphodon stenobyrus (Cope) Chondrichthyes Echinodermata Edaphodon mirificus Leidy Edaphodon agassizi (Buckland) Hemiaster sp. Ischyodus thurmanni Pictet & Campiche Odontaspis sp. Chondrichthyes Squatina sp. Otodus obliquus (Agassiz) Squalicorax pristodontus (Agassiz) Squalicorax pristodontus (Agassiz) Paleocarcharodon sp. Odontaspis sp. Cretolamna appendiculata (Agassiz)