Dukamaje Formation

{{Infobox rockunit

| name = Dukamaje Formation

| image =

| caption =

| type = Geological formation

| age = Maastrichtian

| period = Maastrichtian

| prilithology = Mudstone, shale

| otherlithology = Siltstone, marl, gypsum

| namedfor = Dukamaje, Sokoto, Nigeria

| namedby =

| region = Tahoua
Sokoto

| country = Niger, Nigeria

| coordinates = {{coord|15.4|N|5.8|E|display=inline,title}}

| paleocoordinates = {{coord|5.1|N|0.6|E|display=inline}}

| unitof =

| subunits = Gypsiferous shale Member

| underlies =

| overlies =

| thickness =

| extent = Iullemmeden Basin

| area =

| map = {{Location map+ | Niger

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | Niger

| lat_deg = 15.4

| lon_deg = 5.8

| mark = Lightgreen pog.svg

| marksize = 12

}}

| map_caption =

}}

The Dukamaje Formation is a geological formation in Niger and Nigeria whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 604-605. {{ISBN|0-520-24209-2}}. A wealth of Mosasaur fossils have also been recovered from this formation, particularly from the area around Mt. Igdaman.{{Cite journal|last=Lingham-Soliar|first=Theagarten|year=1991|title=Mosasaurs from the upper Cretaceous of Niger|journal=Palaeontology|volume=34|pages=653–670}}

Fossil content

class="wikitable" align="center"
colspan="5" align="center" \| Dinosaurs of the Dukamaje Formation
Taxa ! Presence ! Description ! Images
Genus: ?Bahariasaurus ?B. ingens. \| Geographically present in Département De Tahoua, Niger. \| \| rowspan="99" \|

class="wikitable" align="center"

colspan="5" align="center" | Dinosaurs of the Dukamaje Formation

Taxa

! Presence

! Description

! Images

Genus:

?Bahariasaurus

?B. ingens.

|

Geographically present in Département De Tahoua, Niger.

|

| rowspan="99" |

class="wikitable" align="center" ! colspan="4" align="center" \| Mosasaurs of the Dukamaje Formation
Taxa !Presence !Description !Images
Genus: Igdamanosaurus I. aegyptiacus \| Geographically present on Mt. Igdaman, near the village of Igdaman (or In Daman). \|Mid-sized globidensine mosasaur.{{Cite journal\|last=Lindgren\|first=Johan\|year=2005\|title=Dental and vertebral morphology of the enigmatic mosasaur Dollosaurus (Reptilia, Mosasauridae) from the lower Campanian (Upper Cretaceous) of southern Sweden\|journal=Bulletin of the Geological Society of Denmark\|volume=52 \|pages=17–25 \|doi=10.37570/bgsd-2005-52-03 \|doi-access=free}} Originally described as a plioplatecarpine. Durophagous. \| rowspan="7" \| File:Goronyosaurus nigeriensis abelov.jpg and juvenile elasmosaurs]]
Genus: Goronyosaurus G. nigeriensis G. sp. \| Type locality unknown. From the portion of the Dukamaje Formation located in Nigeria. Geographically present on Mt. Igdaman. From the portion of the Dukamaje Formation located in Niger. \|Large mosasaur of uncertain affiliations. High number of foramina on the snout and small eyes indicate a murky-water hunter.{{Cite news\|url=https://scienceblogs.com/tetrapodzoology/2009/04/13/tongues-venom-goronyosaurus/\|title=Tongues, venom glands, and the changing face of Goronyosaurus\|newspaper=Tetrapod Zoology\|access-date=2017-01-11}}
Genus: ?Angolasaurus ?A. sp. \| Geographically present on Mt. Igdaman. \|Represented here by four vertebrae, one from a juvenile. Fragmentary state makes identification difficult.
Genus: Halisaurus H. sp. \| Geographically present on Mt. Igdaman. \|Mid-sized mosasaur. Represented here by four vertebrae.
Genus: Plioplatecarpus P. sp. \| Geographically present on Mt. Igdaman. \|Mid-sized plioplatecarpine mosasaur. Represented here by several vertebrae.
Genus: Platecarpus P. sp. \| Geographically present on Mt. Igdaman. \|Mid-sized plioplatecarpine mosasaur. Represented here by a single fragmentary vertebrae.
Genus: Mosasaurus cf. M. hoffmannii \| Geographically present on Mt. Igdaman. \|Massive mosasaurine mosasaur. Represented here by a fragmentary tooth crown. The first example of Mosasaurus from Niger and Nigeria.

class="wikitable" align="center"

! colspan="4" align="center" | Mosasaurs of the Dukamaje Formation

Taxa

!Presence

!Description

!Images

Genus:

Igdamanosaurus

I. aegyptiacus

|

Geographically present on Mt. Igdaman, near the village of Igdaman (or In Daman).

|Mid-sized globidensine mosasaur.{{Cite journal|last=Lindgren|first=Johan|year=2005|title=Dental and vertebral morphology of the enigmatic mosasaur Dollosaurus (Reptilia, Mosasauridae) from the lower Campanian (Upper Cretaceous) of southern Sweden|journal=Bulletin of the Geological Society of Denmark|volume=52 |pages=17–25 |doi=10.37570/bgsd-2005-52-03 |doi-access=free}} Originally described as a plioplatecarpine. Durophagous.

| rowspan="7" |

File:Goronyosaurus nigeriensis abelov.jpg and juvenile elasmosaurs]]

Genus:

Goronyosaurus

G. nigeriensis
G. sp.

|

Type locality unknown. From the portion of the Dukamaje Formation located in Nigeria.
Geographically present on Mt. Igdaman. From the portion of the Dukamaje Formation located in Niger.

|Large mosasaur of uncertain affiliations. High number of foramina on the snout and small eyes indicate a murky-water hunter.{{Cite news|url=https://scienceblogs.com/tetrapodzoology/2009/04/13/tongues-venom-goronyosaurus/|title=Tongues, venom glands, and the changing face of Goronyosaurus|newspaper=Tetrapod Zoology|access-date=2017-01-11}}

Genus:

?Angolasaurus

?A. sp.

|

Geographically present on Mt. Igdaman.

|Represented here by four vertebrae, one from a juvenile. Fragmentary state makes identification difficult.

Genus:

Halisaurus

H. sp.

|

Geographically present on Mt. Igdaman.

|Mid-sized mosasaur. Represented here by four vertebrae.

Genus:

Plioplatecarpus

P. sp.

|

Geographically present on Mt. Igdaman.

|Mid-sized plioplatecarpine mosasaur. Represented here by several vertebrae.

Genus:

Platecarpus

P. sp.

|

Geographically present on Mt. Igdaman.

|Mid-sized plioplatecarpine mosasaur. Represented here by a single fragmentary vertebrae.

Genus:

Mosasaurus

cf. M. hoffmannii

|

Geographically present on Mt. Igdaman.

|Massive mosasaurine mosasaur. Represented here by a fragmentary tooth crown. The first example of Mosasaurus from Niger and Nigeria.

;Other reptiles

Sokotosuchus ianwilsoni[https://paleobiodb.org/classic/displayCollResults?collection_no=82229 Gilbedi Hills, Rima River] at Fossilworks.org
Palaeophis sp.[https://paleobiodb.org/classic/displayCollResults?collection_no=104945 Mont Igdaman (bed 25)] at Fossilworks.org
Podocnemis sp.
Trematochampsa taqueti
Libycosuchus sp.

;Fishes

Asteracanthus aegyptiacus[https://paleobiodb.org/classic/displayCollResults?collection_no=178660 In Touhout (bed 4)] at Fossilworks.org
Igdabatis sigmodon
Lamna nigeriana
Schizorhiza stromeri
Stephanodus lybicus
Stratodus apicalis
Ischyrhiza nigeriensis
Ceratodus sp.
Ginglymostoma sp.
Pycnodus sp.

Dukamaje Formation

Fossil content

See also

References

Further reading