Pabdeh Formation

The Pabdeh Formation is a Late Eocene to Early Oligocene-aged^[1][2] geological formation in Iran. It outcrops along the Zagros Mountains. It was deposited in a deepwater environment in the upper bathyal zone of the Paratethys Sea,^[3] with these abyssal sediments being lifted high above sea level from the uplift of the Zagros fold and thrust belt as part of the Alpide orogeny.

Pabdeh Formation
Stratigraphic range: Late Eocene to Early Oligocene, 37.7–28 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Formation
Unit of	Zagros fold and thrust belt
Underlies	Asmari Formation
Overlies	Gurpi Formation
Lithology
Primary	Marl, limestone
Other	Oil shales
Location
Country	Iran

A high number of fossil fishes are known from this formation, the majority of which appear to have pelagic and deepwater affinities. These are mostly known from two localities near Elam and Istehbanat.^[4] The age of these localities have been disputed, and have previously been considered to be Early Oligocene, but are now generally thought to be middle to late Eocene in age, most likely Priabonian.^[5] Some fossils of migratory insects (a locust and ant alates), as well as fish and birds, are also known from presumed early Oligocene-aged strata near Babaheidar.^[3]

Paleobiota

Cartilaginous fishes

Genus	Species	Notes	Images
Xiphodolamia	X. serrata	A xiphodolamiid shark.[6]

Bony fishes

Based primarily on Arambourg (1967), with taxonomic changes made where necessary:^[4]

Genus	Species	Locality	Notes	Images
Aluvarus	A. praeimperialis	Elam	The larva of a percomorph of uncertain affinities, once thought to be a louvar relative.[7]
Arambourgthurus	A. scombrurus	Istehbanat	A surgeonfish. One of the only known surgeonfish to inhabit a pelagic ecosystem.[8]
?Astronesthes	?A. simus	Elam	An apparent stareater, taxonomic affinity uncertain.
Babelichthys	B. olneyi	Elam	A bizarre crestfish.[9]
Berycomorus	B. firdoussi	Elam	A beryciform.
Bregmaceros	B. filamentosus	Elam	A codlet.
Caucasiganus	C. sp.	Istehbanat	A relative of rabbitfish.[10]
Cheilinus	C. longifillis	Istehbanat	A wrasse.
Cottopsis	C. gaudryi	Elam	An oceanic basslet.[11]
Dussumieria	D. elami	Elam	A rainbow sardine.
Eosternoptyx	E. discoidalis	Elam	A deep-sea hatchetfish.[12]
Epinnula	E. cancellata	Elam	A snake mackerel.
Etrumeus	E. hafizi	Istehbanat	A round herring.
Grammatorcynus	G. scomberoides	Istehbanat, Elam	A mackerel.
Iraniplectus	I. bakhtiari	Babaheidar	A pufferfish-like tetraodontiform.[13]
Maurolicus	M. morgani	Elam	A pearlside.
?Myroconger	?M. rouslami	Elam	An apparent thin eel, taxonomic affinity uncertain.
Opisthonema	O. persicum	Elam	A thread herring.
Palaeorhynchus	P. altivelis	Istehbanat	A palaeorhynchid billfish.
Palimphyes (=Dipterichthys)	P. nematophorus	Elam	A euzaphlegid.[14]
	P. leptosomus
Paucaichthys	P. elamensis	Elam	A pomfret.[15]
Praewoodsia	P. mesogeae	Elam	A bristlemouth.
Priacanthopsis	P. crassispinus	Elam	A bigeye.
Proserrivomer	P. mecquenemi	Elam	A sawtooth eel.
Propteridium	P. douvillei	Elam	A viviparous brotula.
Pristigenys	P. macropus	Istehbanat	A bigeye.
Protolophotus	P. elami	Elam	A crestfish.
?Psenes	?P. macrolepis	Elam	A driftfish, taxonomic identity uncertain.
Pseudoholocentrum	P. cristatum	Elam	A holocentrid.
Rybapina	R. orientalis	Elam	A driftfish.[16][17]
Scomber	S. saadii	Istehbanat	A mackerel.
Scomberomorus	S. speciosus	Istehbanat	A mackerel.
Scopeloides	S. glarisianus	Elam	A bristlemouth.
Sphyraena	S. longimana	Istehbanat	A barracuda.
Thyrsitoides	T. zarathoustrae	Elam	A relative of the blacksail snake mackerel.
?Urosphen	?U. iranensis	Elam	A urosphenid syngnathiform.

Birds

Genus	Species	Locality	Notes	Images
Diomedeoides (=Frigidafrons)	D. babaheydariensis	Babaheidar	A diomedeoidid seabird.[18]

Arthropods

Crustaceans

Based on Garassino, Bahrami, Yazdi & Vega (2014):^[19]

Genus	Species	Locality	Notes	Images
Eogordonella	E. iranianiensis	Babaheidar	A solenocerid shrimp.
Eopabdehus	E. babaheydariensis		A penaeid shrimp.
Parsacus	P. eocenicus		A slipper lobster.

Insecta

Genus	Species	Locality	Notes	Images
Acrididae indet.		Babaheidar	A short-horned grasshopper of uncertain affinities, potentially in a migratory locust-like phase.[3]
Formicidae indet.			A potentially myrmicine ant of uncertain affinities, migratory alates.[3]