Hornerstown Formation

Last updated
Hornerstown Formation
Stratigraphic range: latest Maastrichtian-Danian [1]
66.5–62  Ma
O
S
D
C
P
T
J
K
Pg
N
Type Geological formation
Unit of Rancocas Group
Underlies Vincentown Formation
Overlies New Egypt Formation, Navesink Formation and Tinton Formation
Lithology
Primary Marl, greensand
Location
Region New Jersey
CountryUnited States
Type section
Named for Hornerstown, New Jersey

The Hornerstown Formation is a latest Cretaceous to early Paleocene-aged geologic formation in New Jersey. It preserves a variety of fossil remains, including those of dinosaurs, and contains direct evidence of the mass mortality that occurred at the Cretaceous-Paleogene boundary. [2] [3] [4]

Contents

Outcrops of the Hornerstown Formation are known from sites such as Edelman Fossil Park. [5]

Age & significance

The age of the Hornerstown deposits have been controversial. While most fossils are of animal taxa known from the earliest Cenozoic era, several fossils of otherwise exclusively Cretaceous age have been found. These include remains of the shark Squalicorax , several types of non-avian dinosaurs, the teleost fish Enchodus , several species of ammonite, and marine lizards referred to the genus Mosasaurus . Some of these remains show signs of severe abrasion and erosion, however, implying that they may be re-worked from older deposits. Most of these fossils are restricted to the lowest point in the formation, one rich in fossils and known as the Main Fossiliferous Layer, or MFL. Other explanations for the out-of-place fossils in the MFL is that they represent a time-averaged assemblage that built up and remained unburied during a time of low sediment deposition, or that they were stirred up from deeper in the sediment and deposited together during a tsunami. [6] Biochemical analyses done on mosasaur bones from the Hornerstown Formation and the underlying, purely Cretaceous New Egypt Formation have found differing chemical signatures in the content of rare earth elements depending on whether the bones derive from the New Egypt or the Hornerstown Formation. This provides evidence against the idea that the presence of these remains in the Hornerstown is just the result of reworking, and supports the Hornerstown Formation including Cretaceous strata. [7]

To account for these Cretaceous fossils, the Hornerstown Formation is generally treated as including the last portion of the Maastrichtian shortly before the Cretaceous-Paleogene boundary, and is thus divided into three sections: the section below the MFL (entirely Maastrichtian), the MFL itself (at the K-Pg boundary), and the section above the MFL (entirely Danian). However, other studies continue to treat the Hornerstown Formation as a Paleocene formation that saw significant reworking of Cretaceous fossils into itself. [8] In addition, recent studies have found evidence of high iridium concentration and shocked quartz within the MFL, suggesting that the MFL represents a thanatocoenosis formed from an ecosystem collapse during the Cretaceous-Paleogene extinction event. This makes the Hornerstown Formation one of the few geological formations to contain direct evidence of the immediate impact of the extinction event. The Hornerstown Formation is important paleontologically, as it shows the impact of the K-Pg extinction on the coastal waters of eastern Appalachia, contains many of the last known records of taxa that went extinct at the K-Pg boundary, while also providing evidence of survivorship for the taxa that managed to survive the extinction event. [3]

Vertebrate paleofauna

Cartilaginous fishes

Based on Case (1996) and Boles et al (2024): [3] [9]

Chimaeras

Chimaeras of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
Edaphodon E. agassizi Danian Tooth platesA callorhinchid chimaera. Edaphodon AMNH.jpg
E. mantelliDanian
E. mirificus Maastrichtian
E. stenobyrusMaastrichtian
Ischyodus I. bifurcatusMaastrichtian, potentially DanianTooth plates, jaw elementsA callorhinchid chimaera. Ischyodus quenstedti 45456 (cropped).jpg
I. thurmanniMaastrichtian
I. williamsaeDanian

Sharks

Sharks of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
Araloselachus A. cuspidatusMaastrichtianTeethA sand shark. [10] FOS527C.jpg
Carcharias C. teretidens DanianA relative of the sand tiger shark. Carcharias taurus SI.jpg
Cretalamna C. appendiculataMaastrichtian & DanianA megatooth shark. Cretalamna reconstruction.png
Heptranchias H. howellii MaastrichtianA relative of the sharpnose sevengill shark. Heptranchias perlo (Sharpnose sevengill shark).gif
Hexanchus H. microdon DanianA sixgill shark. Hexanchus griseus (Bluntnose sixgill shark).gif
H. sp.Maastrichtian & Danian
Otodus O. obliquusDanianA megatooth shark. Otodus obliquus.jpg
Odontaspis O. sp.DanianA sand shark. Odontaspis ferox (Smalltooth sand tiger).gif
Palaeocarcharodon P. sp.DanianA megatooth shark. Palaeocarcharodon NT.png
Palaeogaleus P. vincentiMaastrichtian & DanianA houndshark. Palaeogaleus faujasi.jpg
Palaeohypotodus P. rutotiDanianA sand shark. Palaeohypotodus bronni.jpg
Pseudocorax P. affinisMaastrichtianA pseudocoracid shark. Psuedocorax granti.jpg
Scapanorhynchus S. texanusMaastrichtianA goblin shark. [11] Scapanorhynchus sp Sahel Alma Santonian.jpg
Scyliorhinus S. gilberti DanianA catshark. Scyliorhinus retifer.jpg
Sphenodus S. lundgreniMaastrichtianA orthacodontid shark. Sphenodus nitidus.jpg
Squalicorax S. pristodontusMaastrichtianA crow shark. Squalicorax2DB.jpg
Squalus S. minor Maastrichtian & DanianA spurdog. Squalus acanthias.jpg
S. sp
Squatina S. sp.MaastrichtianAn angelshark. Squatina tergocellata.jpg
Weltonia W. ancistrodonDanianA cow shark.
Xampylodon X. brotzeniMaastrichtianA cow shark. Notidanodon.jpg

Rays

Rays of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
Aetomylaeus A. striatus MaastrichtianTeethAn eagle ray. [10] Aetomylaeus maculatus 01.jpg
Dasyatis D. crosswickense DanianA whiptail stingray. Type locality for species. Dasyatis bennettii by jordan and richardson.png
Hypolophites H. hutchinsiDanianA whiptail stingray. Type locality for species.
Hypolophodon H. sylvestrisDanianA whiptail stingray.
Ischyrhiza I. miraMaastrichtianA sclerorhynchid sawskate. [10] Onchosaurus (Ischyrhiza) marrocanus Arambourg 1935 - Dalpiazia stromeri Checcia-Rispoli, 1933 7100.5122.jpg
Rhinoptera R. sp.MaastrichtianA cownose ray. Rhinoptera bonasus (line art).jpg
Rhombodus R. laevisMaastrichtianA rhombodontid ray. Rhombodus NT small cropped.png
Viperecucullus V. kuehneiDanianA whiptail stingray, type locality for the species and genus.

Ray-finned fishes

Actinopterygii of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
Acipenser A. cf. albertensis MaastrichtianA sturgeon. [3] Acipenser oxyrhynchus.jpg
Anomoeodus A. phaseolusMaastrichtian, potentially Danian8 teethA pycnodont. One tooth is known from the Danian section of the formation, which would be the latest record of this genus and prove its occurrence in the Cenozoic; however, it may have been reworked from lower layers. [3] Anomoeodus subclavatus.jpg
Atractosteus A. sp.Maastrichtian & Danian11 teethA gar. First record of gars from eastern North America during the Paleocene. [3] Alligator gar (Atractosteus spatula) I.jpg
cf. Bananogmius cf. B. sp.MaastrichtianA plethodid tselfatiiform. [3] [10] Pentanogmius Bananogmius1DB.jpg
Dercetidae indet.Maastrichtian & Danian27 flank scalesA dercetid aulopiform. The first evidence in eastern North America of the Dercetidae surviving the K-Pg extinction event. [3]
Enchodus E. feroxMaastrichtianAn enchodontid aulopiform. The E. gladiolus remains are the first record of the species in eastern North America. [3] Enchodus petrosus.png
E. gladiolus8 teeth
Iridopristis I. parrisi Sewell, New Jersey Danian3 partial articulated specimens, including a near-complete skull. [8] A stem-lineage member of Holocentridae. The earliest known definitive holocentrid. Type locality for genus and species. [8]
Paralbula P. marylandicaMaastrichtian & Danian23 teethA phyllodontid elopomorph. First evidence of P. marylandica existing during the Cretaceous, indicating that it survived the extinction event. [3]
Phyllodus P. paulkatoiMaastrichtian1 tooth plateA phyllodontid elopomorph. First known occurrence in eastern North America. [3]
Saurocephalus S. lanciformisDanian1 toothA saurodontid ichthyodectiform. First known occurrence in eastern North America and first known occurrence of ichthyodectiforms as a whole in the Paleocene and Cenozoic. [3] Saurocephalus lanciformis.JPG

Reptiles

Birds

A number of fossil birds are known from the greensands of the formation. The Hornerstown serves as the type locality for all these genera and species:

Birds of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceNotes

Anatalavis

A. rex

?earliest Paleocene [12] [13] A waterfowl potentially related to the magpie-goose. [3] [14]

Graculavus

G. velox

A potential wader. [3] [14]

Laornis

L. edwardsianus

A laornithid wading bird. [3] [14]
Novacaesareala N. hungerfordiA potential tropicbird. [3] [14]

Palaeotringa

P. littoralis

A potential wader. [3] [14]

P. vagans

Telmatornis

T. priscus

A potential wader. [3] [14]

Tytthostonyx

T. glauconiticus

A potential seabird. [3] [14]

Non-avian dinosaurs

Dinosaurs of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceNotes
Hadrosauridae indet.MaastrichtianA hadrosaurid ornithischian. [3]

The tyrannosauroid Dryptosaurus is sometimes referred to this formation, as its remains were found in the New Egypt Formation, which is sometimes considered a part of the Hornerstown. [15]

Crocodylomorphs

Crocodylomorphs of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
Borealosuchus B. threeensisMaastrichtianLower jaw, postcranial remainsA eusuchian. Type locality of species. [3] [16] Borealosuchus wilsoni HMNS.jpg

Bottosaurus

B. harlani

Maastrichtian & DanianRemains including lower jaw of a juvenile individual [17] An early caiman. [3] [17]
B. tuberculatus [10] Maastrichtian
Hyposaurus H. rogersiiMaastrichtian & DanianA dyrosaurid. [3] [18]
cf. Procaimanoidea P. sp.MaastrichtianA caiman. [3] NMNH-USNM15996 1.jpg
Thoracosaurus T. neocesariensisMaastrichtian & DanianA gavialoid. [3] Dinosauria - Thoracosaurus 02.jpg

Plesiosaurs

Plesiosaurs of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
" Plesiosaurus ""P." brevifemurMaastrichtianAn indeterminate plesiosaur known from a well-documented specimen, now lost. [19] [20]

Turtles

Testudines of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceNotes Images
Adocus A. agilis [19] MaastrichtianAn adocid. [3] Adocus kirtlandius Gilmore, 1919.jpg
A. beatus
A. syntheticus [19]
Agomphus A. pectoralisMaastrichtianA kinosternoid related to Dermatemys . [3] [21] Agomphus.jpg
Bothremys B. sp.MaastrichtianA bothremydid side-necked turtle. [3]
Euclastes E. wielandiMaastrichtian & DanianA sea turtle. [3] Euclastes sp.jpg
Lytoloma L. jeanesiiMaastrichtianA sea turtle. [19]
Osteopygis O. emarginatusMaastrichtianA macrobaenid. [19]
Peritresius P. ornatusMaastrichtianA sea turtle.
Taphrosphys T. sulcatusMaastrichtianA bothremydid side-necked turtle. [3]
T. strenuus

Mosasaurs

Mosasaurs of the Hornerstown Formation
GenusSpeciesLocationStratigraphic positionAbundanceMaterialNotesImages
Halisaurus H. platyspondylusMaastrichtianA halisaurine. Type locality of the genus and species. Halisaurus arambourgi.jpg
Mosasaurus M. hoffmanni (=Nectoportheus validus) [19] MaastrichtianPterygoid, teeth, vertebrae [3] [7] A mosasaurine. This formation contains some of the last known remains, comprising individuals killed during the mass mortality event that formed the MFL. [3] A very large specimen is known. [7] Mosasaurus 21copy.jpg
Plioplatecarpus P. sp.MaastrichtianA plioplatecarpine. Plioplatecarpus primaevus life reconstruction.jpg

See also

References

  1. Gentry, A.D.; Kiernan, C.R.; Parham, J.F. (2022). "A large non-marine turtle from the Upper Cretaceous of Alabama and a review of North American "Macrobaenids"". The Anatomical Record. 306 (6): 1411–1430. doi:10.1002/ar.25054. PMID   37158131.
  2. Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Boles, Zachary; Ullmann, Paul; Putnam, Ian; Ford, Mariele; Deckhut, Joseph (2024-04-12). "New vertebrate microfossils expand the diversity of the chondrichthyan and actinopterygian fauna of the Maastrichtian–Danian Hornerstown Formation in New Jersey". Acta Palaeontologica Polonica. doi: 10.4202/app.01117.2023 .
  4. Staron, Richard M.; Grandstaff, Barbara S.; Gallagher, William B.; Grandstaff, David E. (2001). "REE Signatures in Vertebrate Fossils from Sewell, NJ: Implications for Location of the K-T Boundary" . PALAIOS. 16 (3): 255–265. doi:10.2307/3515603. ISSN   0883-1351.
  5. Voegele, Kristyn K.; Ullmann, Paul V.; Lonsdorf, Tara; Christman, Zachary; Heierbacher, Michael; Kibelstis, Brian J.; Putnam, Ian; Boles, Zachary M.; Walsh, Shane; Lacovara, Kenneth J. (2021-11-01). "Microstratigraphic Analysis of Fossil Distribution in the Lower Hornerstown and Upper Navesink Formations at the Edelman Fossil Park, NJ". Frontiers in Earth Science. 9: 1033. Bibcode:2021FrEaS...9.1033V. doi: 10.3389/feart.2021.756655 . ISSN   2296-6463.
  6. Gallagher, W.B. (2005). "Recent mosasaur discoveries from New Jersey and Delaware, USA: stratigraphy, taphonomy and implications for mosasaur extinction." Netherlands Journal of Geosciences — Geologie en Mijnbouw, 84(3): 241-245. Archived 2012-09-04 at the Wayback Machine
  7. 1 2 3 Gallagher, W. B. (2015). "Greensand mosasaurs of New Jersey and the Cretaceous–Paleogene transition of marine vertebrates". Netherlands Journal of Geosciences. 94 (1): 87–91. Bibcode:2015NJGeo..94...87G. doi:10.1017/njg.2014.30. ISSN   0016-7746.
  8. 1 2 3 Andrews, J. V.; Schein, J. P.; Friedman, M. (2023). "An earliest Paleocene squirrelfish (Teleostei: Beryciformes: Holocentroidea) and its bearing on the timescale of holocentroid evolution". Journal of Systematic Palaeontology. 21 (1). Bibcode:2023JSPal..2168571A. doi: 10.1080/14772019.2023.2168571 .
  9. Case, Gerard R. (1996-12-19). "A new Selachian Fauna from the Lower Hornerstown Formation (Early Paleocene/Montian) of Monmouth County, New Jersey" . Palaeontographica Abteilung A. 242 (1–3): 1–14. Bibcode:1996PalAA.242....1C. doi:10.1127/pala/242/1996/1.
  10. 1 2 3 4 5 "PBDB Collection". paleobiodb.org. Retrieved 2024-11-12.
  11. "PBDB Collection". paleobiodb.org. Retrieved 2024-11-12.
  12. Olson, S. (1994). "A giant Presbyornis (Aves: Anseriformes) and other birds from the Paleocene Aquia Formation of Maryland and Virginia". Proceedings of the Biological Society of Washington. 107: 429–435. hdl:10088/6493.
  13. Brocklehurst, Neil; Upchurch, Paul; Mannion, Philip D.; O'Connor, Jingmai (2012-06-25). "The Completeness of the Fossil Record of Mesozoic Birds: Implications for Early Avian Evolution". PLOS ONE. 7 (6): e39056. Bibcode:2012PLoSO...739056B. doi: 10.1371/journal.pone.0039056 . ISSN   1932-6203. PMC   3382576 . PMID   22761723.
  14. 1 2 3 4 5 6 7 "3.22 New Jersey, United States; 7. Hornerstown Formation," in Weishampel, et al. (2004). Page 586.
  15. Olsson, R.K. (1960). "Foraminifera of latest Cretaceous and earliest Tertiary age in the New Jersey coastal plain". Journal of Paleontology. 34: 1–58.
  16. Brochu, Christopher A.; Parris, David C.; Grandstaff, Barbara Smith; Denton, Robert K.; Gallagher, William B. (2012). "A new species of Borealosuchus (Crocodyliformes, Eusuchia) from the Late Cretaceous–early Paleogene of New Jersey" . Journal of Vertebrate Paleontology. 32 (1): 105–116. Bibcode:2012JVPal..32..105B. doi:10.1080/02724634.2012.633585. ISSN   0272-4634.
  17. 1 2 Cossette, A. P., and C. A. Brochu. 2018. A new specimen of the alligatoroid Bottosaurus harlani and the early history of character evolution in alligatorids. Journal of Vertebrate Paleontology. DOI:10.1080/02724634.2018.1486321.
  18. Morgan, Donald J (December 2018). "PRESENCE OF A DYROSAURID NEOSUCHIAN IN THE SEVERN/BRIGHTSEAT FORMATION OF MARYLAND". The Journal of the Delaware Valley Paleontological Society. X: 91 to 104.
  19. 1 2 3 4 5 6 "PBDB Collection". paleobiodb.org. Retrieved 2024-11-12.
  20. Parris, David C. (1974). "Additional Records of Plesiosaurs from the Cretaceous of New Jersey". Journal of Paleontology. 48 (1): 32–35. ISSN   0022-3360. JSTOR   1303102.
  21. "PBDB Taxon". paleobiodb.org. Retrieved 2024-11-11.

Bibliography