Paleobiota of the Niobrara Formation
During the time of the deposition of the Niobrara Chalk, much life inhabited the seas of the Western Interior Seaway. By this time in the Late Cretaceous many new lifeforms appeared such as mosasaurs, which were to be some of the last of the aquatic lifeforms to evolve before the end of the Mesozoic. Life of the Niobrara Chalk is comparable to that of the Dakota Formation, although the Dakota Formation, which was deposited during the Cenomanian, predates the chalk by about 10 million years.
Table key
Color | Explanation |
---|---|
Light grey | A "regular" taxon which the scientific consensus does not regard as a dubious, synonymous, undescribed, or otherwise taxonomically questionable name. |
Dark grey | A taxon or parataxon that is misidentified, dubious, synonymous, undescribed, or otherwise taxonomically questionable name. |
Peach | An ichnotaxon, a parataxon representing a specific kind of trace fossil. |
Light blue | An ootaxon, a parataxon representing a specific kind of fossil egg. |
Light green | A morphotaxon, a parataxon representing a single stage or anatomical part of a plant or plant-like organism. Examples include fossil pine cones, fungal spores, and leaves. |
Bony fish
Pycnodontiformes
Genus | Species | Member | Abundance | Notes |
---|---|---|---|---|
Micropycnodon[1] | M. kansasensis[1] | Smoky Hill Chalk[1] | A pycnodontiform fish similar but unrelated to modern parrotfish |
Semionotiformes
Genus | Species | Member | Abundance | Notes |
---|---|---|---|---|
H. marshi[1] | Smoky Hill Chalk[1] | Family Hadrodontidae Thurmond and Jones 1981 |
Pachycormiformes
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
Protosphyraena[1] | P. bentonianum | A pachycormid
|
|||
P. nitida[1] | Smoky Hill Chalk[1] | ||||
P. perniciosa[1] | Smoky Hill Chalk[1] | ||||
P. tenuis[1] | Smoky Hill Chalk[1] | ||||
P. gladius[1] | Smoky Hill Chalk[1] | Named as a new genus, Bonnerichthys | |||
Bonnerichthys[2] | B. gladius | Smoky Hill Chalk[3] | A filter feeding pachycormid |
Crossognathiformes
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
Apsopelix[3] | A. anglicus[3] | Smoky Hill Chalk[3] | A crossognathid .
|
||
Pachyrhizodus[3] | P. caninus[3] | Smoky Hill Chalk[3] | A pachyrhizodontid
| ||
P. leptopsis[3] | Smoky Hill Chalk[3] | ||||
P. minimus[3] | Smoky Hill Chalk[3] |
Ichthyodectiformes
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
Xiphactinus[3] | X. audax[3] | Smoky Hill Chalk[3] | A large ichthyodectid
|
||
Ichthyodectes[3] | I. ctenodon[3] | Smoky Hill Chalk[3] | An ichthyodectid | ||
Gillicus[3] | G. arcuantus[3] | Smoky Hill Chalk[3] | A saurodontid
| ||
Saurodon[3] | S. leanus[3] | Smoky Hill Chalk[3] | A saurodontid | ||
Saurocephalus[3] | S. lanciformis[3] | Smoky Hill Chalk[3] | A saurodontid |
Tselfatiiformes
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
Thryptodus[3] | T. zitteli[3] | Smoky Hill Chalk[3] | A plethodid | ||
Pentanogmius[3] | P. evolutus[3] | Smoky Hill Chalk[3] | A plethodid | ||
Martinichthys[3] | M. brevis[3] | Smoky Hill Chalk[3] | A plethodid | ||
M. xiphoides[3] | Smoky Hill Chalk[3] | ||||
Niobrara[3] | N. encarsia[3] | Smoky Hill Chalk[3] | A plethodid | ||
Zanclites[3] | Z. xenurus[3] | Smoky Hill Chalk[3] | A plethodid |
Aulopiformes
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
Cimolichthys[3] | C. nepaholica[3] | Smoky Hill Chalk[3] | A cimolichthyid
|
||
E. dirus[3] | Smoky Hill Chalk[3] | An enchodontid | |||
E. gladiolus[3] | Smoky Hill Chalk[3] | ||||
E. petrosus[3] | Smoky Hill Chalk[3] | ||||
E. shumardi[3] | Smoky Hill Chalk[3] | ||||
Apateodus[3] | Indeterminate[3] | Smoky Hill Chalk[3] | An | ||
Stratodus[3] | S. apicalis[3] | Smoky Hill Chalk[3] | An alepisauriform actinopterygiian
| ||
Leptecodon[3] | L. rectus[citation needed] | An alepisauriform actinopterygiian
|
Beryciformes
Genus | Species | Member | Abundance | Notes |
---|---|---|---|---|
Kansius[3] | K. sternbergi[3] | Smoky Hill Chalk[3] | A beryciform actinopterygiian | |
Trachichthyoides[3] | Indeterminate[3] | Smoky Hill Chalk[3] | A beryciform actinopterygiian | |
Caproberyx[3] | Indeterminate[3] | Smoky Hill Chalk[3] | A beryciform actinopterygiian |
Other bony fish
Genus | Species | Member | Abundance | Notes |
---|---|---|---|---|
Indeterminate[1] | Smoky Hill Chalk[1] | A lepisosteid gar
| ||
Paraliodesmus[3] | P. guadagnii[3] | Smoky Hill Chalk[3] | An amiiform
| |
Urenchelys[3] | U. abditus[3] | Smoky Hill Chalk[3] | An anguilliform
| |
Ferrifrons | F. rugosus | A ferrifronsid acanthomorph | ||
Aethocephalichthys[3] | A. hyainarhinos[3] | Smoky Hill Chalk[3] | An actinopterygian of indeterminate classification[4] | |
Omosoma | O. garretti | A polymixiid actinopterygiian closely related to the modern Beardfish | ||
Belonostomus[1] | Indeterminate[1] | An aspidorhynchid
|
Cartilaginous fish
Fish are by far the most common fossils found from the formation, with remains of prehistoric
.Sharks
Genus | Species | State | Member | Abundance | Notes | Images |
---|---|---|---|---|---|---|
C. mantelli[5] | Smoky Hill Chalk[5] | A large lamniform shark | ||||
C. appendiculata[6] | Smoky Hill Chalk[6] | A lamniform shark
|
||||
|
C. appendiculata[5] |
N/A | N/A | N/A | An extremely widely used lapsus calami for Cretalamna.[7]
|
|
Johnlongia[5] | Indeterminate[5] | Smoky Hill Chalk[5] | An odontaspidid lamniform shark
|
|||
Pseudocorax[5] | P. laevis[5] | Smoky Hill Chalk[5] | A lamniform shark smaller than Cretoxyrhina | |||
Squalicorax[5] | S. falcatus[5] | Smoky Hill Chalk[5] | A lamniform | |||
S. kaupi[5] | Smoky Hill Chalk[5] | |||||
S. pristodontus[5] | Smoky Hill Chalk[5] | |||||
Scapanorhynchus[5] | S. raphiodon[5] | Smoky Hill Chalk[5] | A mitsukurinid shark similar in appearance to the modern day goblin shark | |||
Ptychodus[5] | P. anonymus[5] | Smoky Hill Chalk[5] | A hybodontoid shark
|
|||
P. martini[5] | Smoky Hill Chalk[5] | |||||
P. mortoni[5] |
Smoky Hill Chalk[5] | |||||
P. occidentalis[5] | Smoky Hill Chalk[5] | |||||
P. polygyrus[5] | Smoky Hill Chalk[5] |
Other cartilaginous fish
Genus | Species | State | Member | Abundance | Notes | Images |
---|---|---|---|---|---|---|
E. laqueatus[citation needed] |
A ratfish
|
|||||
Rhinobatos[5] | R. incertus[5] | Smoky Hill Chalk[5] |
Dinosaurs
Nonavian dinosaurs have been found in the Niobrara Chalk despite it being located hundreds of miles out to sea at the time. The most reasonable theory is that the carcasses drifted out to sea. It is unlikely that the bodies were carried out by outgoing tides along the shorelines where they died, but rather it is more probable that the dinosaurs were carried offshore by floodwaters during a storm. In the shallow waters the bodies would have begun to decompose and bacteria within the carcass would have produced gasses that would have accumulated in the gut, thereby making the body buoyant. Next, the prevailing winds and currents would have carried it out to sea, where it would eventually settle to the bottom and be buried in sediment.[8]
A few
Non-avian
Genus | Species | State | Member | Material | Notes | Images |
---|---|---|---|---|---|---|
C. agilis[12] |
Kansas[13] | Smoky Hill Chalk[12] |
"Single articulated postcranial skeleton with associated skull fragments."[14] |
A small hadrosaurid
|
||
Indeterminate hadrosaurid[15]
|
A hadrosaurid of indeterminate classification. Possibly Corythosaurus.[15]
| |||||
N. coleii[12] |
Kansas[13] | Smoky Hill Chalk[12] | "Partial skeleton."[16] | A nodosaurid ankylosaur. | ||
Hierosaurus[12] | H. sternbergi[12] | Kansas[13] | Smoky Hill Chalk[12] | "Osteoderms."[17] | A nodosaurid ankylosaur. |
Birds
Three genre of birds are present in the formation, although rare. They were unrelated to modern birds, as they still retained teeth. Baptornis and Hesperornis were large flightless aquatic birds suited for diving. Ichthyornis was a seabird that resembled the gulls and petrels of today. Both probably preyed on small fish and were preyed upon by sharks, large bony fish such as Xiphactinus, and mosasaurs.
Genus | Species | State | Member | Material | Notes | Images |
---|---|---|---|---|---|---|
Apatornis[18] | A. celer[18] | Smoky Hill Chalk[18] | "Postcranial elements."[20] | |||
Baptornis[18] | B. advenus[18] | Smoky Hill Chalk[18] | "Fragmentary skull [and] nearly complete postcranium."[21] | A hesperornithiform
| ||
Guildavis[18] | G. tener[18] | Smoky Hill Chalk[18] | ||||
H. crassipes[13] | Kansas[13] | "Partial postcranial skeleton."[21] | ||||
H. gracilis[13] | Kansas[13] | "Tarsometatarsus."[21] | ||||
H. regalis[18] |
Kansas[13] | Smoky Hill Chalk[18] | A large hesperornithiform
| |||
Iaceornis[18] | I. marshi[18] | Smoky Hill Chalk[18] | ||||
I. agilis[13] |
Kansas[13] | Junior synonym of I. dispar.[13] | ||||
I. anceps[13] | Kansas[13] | Junior synonym of I. dispar.[13] | ||||
I. dispar[18] |
Kansas[13] | Smoky Hill Chalk[18] | An ichthyornithid
| |||
I. lentus[13] | Kansas[13] | |||||
I. tener[13] | Kansas[13] | |||||
I. validus[13] |
Kansas[13] | Junior synonym of I. dispar.[13] | ||||
I. victor[13] | Kansas[13] | Junior synonym of I. dispar.[13] | ||||
Parahesperornis[18] | P. alexi[18] | Kansas[13] | Smoky Hill Chalk[18] | "Partial skull [and] complete postcranium."[21] |
Invertebrates
Bivalves
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
C. undulatoplicatus[22] |
Smoky Hill Chalk[22] | ||||
D. maxima[22] |
Smoky Hill Chalk[22] | ||||
Fort Hays Limestone[23] | |||||
Fort Hays Limestone[23] | |||||
Ostrea[23] | Fort Hays Limestone[23] | ||||
P. platinus[22] |
Smoky Hill Chalk[22] | ||||
P. congesta[22] |
Smoky Hill Chalk[22] | ||||
V. grandis[22] | Smoky Hill Chalk[22] |
Cephalopods
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
Smoky Hill Chalk[22] | |||||
Clioscaphites[22] | Smoky Hill Chalk[22] | ||||
Rugaptychus[22] | Smoky Hill Chalk[22] | ||||
Spinaptychus[22] | Smoky Hill Chalk[22] | ||||
Tusoteuthis[22] | T. longa | Smoky Hill Chalk[22] | A nomen dubium.[24] | ||
Enchoteuthis | E. melanae | Smoky Hill Chalk | Most material formerly referred to Tusoteuthis now belongs to this taxon.[24] | ||
E. cobbani | Smoky Hill Chalk | ||||
Niobrarateuthis | N. bonneri | Smoky Hill Chalk |
Echinoderms
Genus | Species | State | Member | Abundance | Notes |
---|---|---|---|---|---|
"Unitacrinus"[22] | "U. socialis"[22] | N/A | N/A | N/A | Common lapsus calami of Uintacrinus
|
Uintacrinus |
Mosasaurs
Mosasaurs are the most common marine reptiles in the Niobrara Chalk and the most successful ones in the sea at the time. Several different genera representing the four different subfamilies of Mosasauridae: the Tylosaurinae, Plioplatecarpinae, Mosasaurinae, and Halisaurinae, were present in Niobrara. They were the dominant carnivorous marine reptiles and ate cephalopods, fish, turtles, pterosaurs, birds, and even plesiosaurs.[26] There is evidence of them consuming other smaller mosasaurs. Despite this, mosasaurs often fell prey to some of the large sharks at the time, such as Cretoxyrhina.[27]
The presence of young mosasaurs in the formation suggests that mosasaurs were viviparous and gave birth hundreds of miles out to sea, as Niobrara was in the middle of the Western Interior Seaway at the time.[28] Juveniles would likely have been vulnerable to predation by the many large mid-ocean predators present in the ecosystem.
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
C. liodontus[29] | Smoky Hill Chalk[29] | ||||
C. prophython[29] | Smoky Hill Chalk[29] | ||||
E. clidastoides[30] | Smoky Hill Chalk[30] | ||||
E. everhartorum[31] | Smoky Hill Chalk | ||||
E. tlemonectes[32] | Smoky Hill Chalk | ||||
Eonatator | E. sternbergii | Smoky Hill Chalk[29] | A small halisaurine | ||
Platecarpus[30] | P. tympaniticus[30] | Smoky Hill Chalk[30] | A plioplatecarpine | ||
Plesioplatecarpus | P. planifrons[30] | Smoky Hill Chalk[30] | |||
T. nepaeolicus[30] |
Smoky Hill Chalk[30] | A large tylosaurine, with the largest T. proriger reaching about 13 metres in length. | |||
T. proriger[30] | Smoky Hill Chalk[30] | ||||
Selmasaurus[33] | S. johnsoni | Smoky Hill Chalk |
Plesiosaurs
Plesiosaurs are present from two different families within
Genus | Species | State | Member | Time span | Notes | Images |
---|---|---|---|---|---|---|
P. latipinnis[35] | Smoky Hill Chalk[35] | 84.5-81.5 Ma ago[36] | A polycotylid. | |||
Dolichorhynchops[35] | D. osborni[35] | Smoky Hill Chalk[35] | 84.5-81.5 Ma ago[36] | A Pierre Shale Formation
| ||
Brimosaurus[37] | B. grandis | Kansas[37] | Fort Hays Limestone[37] | A nomen dubium. | ||
Styxosaurus[35] | S. snowii[35] | Smoky Hill Chalk[35] | 85-81.5 Ma ago[36] | A large elasmosaurid, also present in the Pierre Shale Formation | ||
Elasmosaurus[35] | "E." sternbergi[35] | Smoky Hill Chalk[35] | 84.5-81.5 Ma ago | Most likely not referable to Elasmosaurus. |
Pterosaurs
Two genre of pterosaurs are present in the formation, both within
Genus | Species | Member | Time span | Notes | Images |
---|---|---|---|---|---|
N. gracilis[39] |
Smoky Hill Chalk[39] | 85–84.5 Ma ago[36] | A ornithocheiroid .
|
||
P. longiceps[39] | Smoky Hill Chalk[39] | 86–84.5 Ma ago[36] | A large and very abundant ornithocheiroid .
| ||
|
G. sternbergi | Smoky Hill Chalk | 86–84.5 Ma ago | A species of Pterosaur that is regarded by a few Paleontologists to be a species of Pteranodon, though most regard it as a distinct species. | |
Turtles
Sea turtles have been found from the Niobrara Chalk that reached large sizes. The biggest, Archelon, was considerably larger than its distant relative, the leatherback sea turtle, which is the largest of the sea turtles alive today. The sea turtles most likely fed on ammonites, squid, and other cephalopods.
Genus | Species | Member | Abundance | Notes | Images |
---|---|---|---|---|---|
B. barberi[41] |
Smoky Hill Chalk[41] | ||||
Chelosphargis[41] | C. advena[41] | Smoky Hill Chalk[41] | |||
C. stenopora[41] |
Smoky Hill Chalk[41] | ||||
Porthochelys[41] | P. laticeps[41] | Smoky Hill Chalk[41] | A toxichelid cryptodire | ||
Protostega[41] | P. gigas[41] | Smoky Hill Chalk[41] | A protostegid cryptodire | ||
Toxochelys[41] | T. latiremis[41] | Smoky Hill Chalk[41] | A chelonioid cryptodire
|
Footnotes
- ^ a b c d e f g h i j k l m n o p q r s t "Table 13.1: Bony Fish", Everhart (2005), page 244.
- ^ Viegas, Jennifer (18 February 2010), SUV-Sized Fish Were Earliest Filter-Feeders, Discovery News, retrieved 1 April 2010
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz ca cb "Table 13.1: Bony Fish", Everhart (2005), page 245.
- ^ Fielitz, C.; Stewart, J. D.; & Wiffen, J. 1999. Aethocephalichthys hyainarhinos gen. et sp. nov., a new and enigmatic Late Cretaceous actinopterygian from North America and New Zealand. Mesozoic Fishes 2 – Systematics and Fossil Record, G. Arratia & H.-P. Schultze (eds.): pp. 95-106, 7 figs.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai "Table 13.1: Sharks/Rays", Everhart (2005), page 244
- ^ lapsus calamiCretolamna.
- ^ "Introduction", in "Skeletal and Dental Anatomy..." Shimada (2007), page 584
- ^ "Niobrarasaurus". Oceansofkansas.com. Retrieved 2016-04-13.
- ^ "Shark bit dino". Oceansofkansas.com. Retrieved 2016-04-13.
- ^ Everhart, M. J. and K. Ewell. 2006. Shark-bitten dinosaur (Hadrosauridae) vertebrae from the Niobrara Chalk (Upper Coniacian) of western Kansas. Kansas Academy of Science, Transactions, 109 (1-2):27-35.
- doi:10.26879/801. Retrieved 21 March 2021.
- ^ a b c d e f g h i "Table 13.1: Dinosaurs", Everhart (2005), page 246.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa "Dinosaur distribution (Late Cretaceous; North America; Kansas; Niobrara Chalk Formation)." Weishampel, et al. (2004). Pp. 582.
- ^ "Table 20.1," in Weishampel, et al. (2004). Page 439.
- ^ S2CID 86366930.
- ^ "Table 17.1," in Weishampel, et al. (2004). Page 367.
- ^ "Table 17.1," in Weishampel, et al. (2004). Page 368.
- ^ a b c d e f g h i j k l m n o p q r s t u "Table 13.1: Birds," Everhart (2005), page 246.
- ^ "Dinosaur distribution (Late Cretaceous; North America; Nebraska; Niobrara Chalk Formation)." Weishampel, et al. (2004). Pp. 586.
- ^ "Table 11.1," in Weishampel, et al. (2004). Page 214.
- ^ a b c d "Table 11.1," in Weishampel, et al. (2004). Page 215.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa "Table 13.1: Invertebrates," Everhart (2005), page 244.
- ^ a b c d e f "Material: YPM 1640," in "The Occurrence of Elasmosaurids..." Everhart (2006), page 172.
- ^ S2CID 198256507.
- ^ "Tylosaur food". Oceansofkansas.com. 2004-09-26. Retrieved 2016-04-13.
- ^ Everhart, M. J. 2002. New data on plesiosaur remains found as stomach contents of a Tylosaurus proriger (Squamata; Mosasauridae) from the Niobrara Formation of western Kansas. (Abstract) Transactions of the Kansas Academy of Science
- ^ Everhart, M. J. 2004. Late Cretaceous interaction between predators and prey. Evidence of feeding by two species of shark on a mosasaur. PalArch, vertebrate palaeontology series 1(1):1-7.
- ^ Everhart, M. J. 2002. Remains of immature mosasaurs (Squamata; Mosasauridae) from the Niobrara Chalk (Late Cretaceous) argue against nearshore nurseries. (Abstract) Journal of Vertebrate Paleontology 22(suppl. to 3):52A.
- ^ a b c d e f "Table 13.1: Mosasaurs", Everhart (2005), page 245.
- ^ a b c d e f g h i j k l m "Table 13.1: Mosasaurs", Everhart (2005), page 246.
- .
- ISSN 0031-0298.
- ^ Polcyn, M. J., and Everhart, M. J., 2008, Description and phylogenetic analysis of a new species of Selmasaurus (Mosasauridae: Plioplatecarpinae) from the Niobrara Chalk of western Kansas: In: Proceedings of the Second Mosasaur Meeting, edited by Everhart, M. J, Fort Hays Studies, Special Issue number 3, p. 13-28.
- ^ "Field Guide, Part 3; Marine reptiles". Oceansofkansas.com. 2011-01-25. Retrieved 2016-04-13.
- ^ a b c d e f g h i j k l "Table 13.1: Plesiosaurs," Everhart (2005), page 245.
- ^
- ^ a b c "Material: YPM 1640," in "The Occurrence of Elasmosaurids..." Everhart (2006), page 173.
- ISBN 0691150613.
- ^ a b c d e f "Table 13.1: Pterosaurs," Everhart (2005), page 246.
- ^ "Geosternbergia". Pteros. Pteros. Retrieved 28 August 2022.
- ^ a b c d e f g h i j k l m n o p q r "Table 13.1: Turtles," Everhart (2005), page 245.
References
- Everhart, Michael J. Oceans Of Kansas: A Natural History Of The Western Interior Sea (Life of the Past). Bloomington: Indiana University Press, 2005. 322 pp.
- Everhart, Michael J. 2006. "The Occurrence of Elasmosaurids (Reptilia: Plesiosauria) in the Niobrara Chalk of Western Kansas"; Paludicila; 5(4) pp. 170–183
- Shimada, K. 2007. "Skeletal and dental anatomy of lamniform shark, Cretalamna appendiculata from Upper Cretaceous Niobrara Chalk of Kansas". Journal of Vertebrate Paleontology, 27(3):584–602.
- Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.