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Lower pharyngeal jaw of a cichlid fish (Actinopterygii Labroidei) from an earlyOligocene site in the Fayum EgyptAuthor(s) ALISON M MURRAYSource Journal of Vertebrate Paleontology 22(2)453-455 2002Published By The Society of Vertebrate PaleontologyDOI httpdxdoiorg1016710272-4634(2002)022[0453LPJOAC]20CO2URL httpwwwbiooneorgdoifull1016710272-4634282002290225B04533ALPJOAC5D20CO3B2

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453

Journal of Vertebrate Paleontology 22(2)453ndash455 June 2002q 2002 by the Society of Vertebrate Paleontology

NOTE

LOWER PHARYNGEAL JAW OF A CICHLID FISH (ACTINOPTERYGII LABROIDEI) FROM AN EARLY OLIGOCENESITE IN THE FAYUM EGYPT

ALISON M MURRAY Research Division Canadian Museum of Nature PO Box 3443 Station D Ottawa Ontario Canada K1P 6P4

African fossil cichlids are known from deposits ranging in age fromEocene through to Quaternary The Eocene cichlids five species ofMahengechromis are from deposits in Tanzania dated at 45 My old(Murray 2000) Fossil cichlids probably of Oligocene age Macfadyenadabanensis and four indeterminate forms have come from Somalia(Van Couvering 1982) Van Couvering (1982) also reported on isolatedelements from the Early Miocene of Uganda which were identified asrepresenting two or more species referred to Pelmatochromis and ar-ticulated skeletons of similar age from Kenya which she described asPalaeofulu kuluensis Nderechromis cichloides and Kalyptochromis ha-mulodentis Deposits in Kenya have also produced isolated elements ofindeterminate cichlids dated as possibly Early and Late Miocene (VanCouvering 1982) Late Miocene cichlids from Africa are Oreochromismartyni from Kenya Palaeochromis darestei and P rousselleti fromAlgeria and unnamed remains from Kenya Tanzania and Tunisia(Greenwood 1973 Van Couvering 1982 Stewart 1997) Pliocene andPleistocene cichlid remains include isolated bones and fragments ofindeterminate species (eg Murray and Stewart in press) and morecomplete remains referable to Recent tilapiine genera (eg Murray andStewart 1999) Lack of fossil cichlids from western Africa is probablybecause of a lack of deposits of an appropriate age or nature The onlyfossil remains of cichlids previously reported from Egypt are isolatedelements predominantly fin spines pterygiophores and vertebral cen-tra known from Pleistocene deposits at Wadi Natrun (Greenwood1972) Although a number of fossil cichlids are known from Africaadditional cichlid material is necessary to better document the range ofcichlids in past times

Fossil vertebrates including fishes have been reported from the Fa-yum Depression of Egypt in the Western Desert about 80 km southwestof Cairo for over 100 years Although several teleostean fishes havebeen described from the Fayum most of these are from the deposits ofthe Eocene Qasr el Sagha and Birket Qarun formations These depositsare overlain by the Jebel Qatrani Formation from which Dr ElwynSimons of Duke University has been actively collecting fossils for sev-eral decades

The Jebel Qatrani Formation contains deposits ranging from LateEocene through Oligocene in age The only fish remains that have beenreported from this formation are bones of catfishes and lungfishes(Stromer 1916 Peyer 1928) The collections made by Dr Simons andhis team include a large amount of fish material from several localitiesin the Jebel Qatrani Formation From one of these sites Quarry E DrSimons collected a lower pharyngeal jaw of a fish that is here identifiedas belonging to a cichlid

GEOLOGY

The Jebel Qatrani Formation was previously considered to representfluvio-marine conditions (eg Peyer 1928) however Bown and Kraus(1988) found that the formation represents almost completely fluvialconditions Kappelman et al (1992) determined that the Jebel Qatraniwas laid down in alluvial conditions during the retreat of the TethysSea The formation is separated by the Barite Sandstone into upper andlower parts Quarry E from which came the pharyngeal jaw is in thelower part just below the Barite Sandstone roughly 90ndash95 m abovethe base of the formation (Bown and Kraus 1988) Quarry E is in thebottom quarter of the lsquoupper gravelly sandstonersquo which has been inter-preted as channel and floodplain deposits with abundant meanderingrivers and sinuous streams in an area that was not far from the coastline

(Bown and Kraus 1988) The environment of the area during depositionwas probably that of a tropical forest with abundant vegetation that mayhave had monsoonal wet seasons (Bown and Kraus 1988) The sedi-ments from which the pharyngeal jaw comes have been dated as be-tween 3377 and 3512 Ma based on paleomagnetic data (Kappelman1992) which places it in the earliest Oligocene

DESCRIPTION

The specimen from the collections of the Duke University PrimateCenter (catalog number DUPC 4973) is a lower pharyngeal jaw formedby the fused left and right fifth ceratobranchial bones (Fig 1) The jawis broken anteriorly and the left horn is missing The complete righthorn is short but slender and the dentigerous surface of the lower pha-ryngeal jaw is triangular

To the right of the midline in a longitudinal row are two large flat-tened teeth and two tooth sockets (Fig 1A) Lateral to this row is asecond parallel set of two slightly smaller teeth of similar morphologyand two empty sockets Both rows progressively decrease in size an-teriorly This pattern of teeth or sockets is reflected to the left of themidline The surface of the preserved teeth show no signs of cusps orridges Many other tooth sockets some with tooth bases are presentand diminish in size towards the periphery of the jaw Modern cichlidsusually bear more than one type of tooth on the lower pharyngeal jawand it is probable that these smaller marginal teeth would have been ofa different form

On the ventral surface of the jaw (Fig 1B) the left and right halvesare united by a sinuous interdigitating suture The bone surface is par-tially broken through in two areas with the hollow underside of thelarge flattened tooth visible through the hole on the right half A keelis present on the ventral surface of the jaw (Fig 1B C)

DISCUSSION

Several groups of fishes are known to have a united left and rightceratobranchial forming a lower pharyngeal jaw including members ofthe suborder Labroidei Although the monophyly of the Labroidei hasrecently been disputed by a molecular analysis (Streelman and Karl1997) the lower pharyngeal jaw in these fishes can be distinguishedfrom other fishes by the presence of a median keel on the ventral surface(Stiassny and Jensen 1987) This keel is present in the Fayum speci-men The families contained within the Labroidei are the EmbiotocidaeLabridae Pomacentridae and Cichlidae (the families Odacidae andScaridae were subsumed as subfamiles of the Labridae Kaufmann andLiem 1982) As noted by Stiassny and Jensen (1987) the lower pha-ryngeal jaw in almost all cichlids bears an interdigitating suture on theventral surface In non-cichlid labroids there is complete fusion betweenthe left and right fifth ceratobranchials which leaves no trace of a centralsuture and in these families the lower pharyngeal jaw tooth rows arearranged with teeth located directly over the symphysis of the left andright halves (Kaufmann and Liem 1982 pers obs) The Fayum spec-imen clearly shows a median interdigitating suture on the ventral sur-face and there are no teeth positioned over the symphysis Based onthe suture and the placement of the teeth the Fayum lower pharyngealjaw is considered to have belonged to a cichlid fish The environmentof the deposits further supports this identification as the only labroidsfound in fresh water are cichlids and a single embiotocid (Nelson1994)

454 JOURNAL OF VERTEBRATE PALEONTOLOGY VOL 22 NO 2 2002

FIGURE 1 Photographs of DUPC 4973 the lower pharyngeal jaw ofa cichlid fish A dorsal (occlusal) view B ventral view C lateral viewAnterior is towards the bottom in A and B and towards the right in CScale bar 5 5 mm

Only one subgroup of cichlids has been potentially characterized byfeatures of the lower pharyngeal jaw These are the tilapiine cichlidsin which Stiassny (1991) noted the lower pharyngeal jaw usually hastwo foramina one on either side of the median ventral suture and araised ridge on the anterodorsal aspect of the bone There are no foram-ina present on the Fayum specimen and there is no evidence of amedian ridge of bone on the dorsal surface of the jaw but the area inwhich the tilapiine cichlids have this ridge is mostly missing in theFayum specimen Although some individual tilapiines lack the foram-ina the robust dentition of the Fayum specimen in combination withthe lack of foramina stongly indicates that it is not a tilapiine (Stiassnypers comm)

Pharyngeal teeth can vary greatly within a species or genus (egStiassny 1989 Snoeks 1994) and therefore might not be useful toellucidate the relationships of the fossil jaw However hypertrophiedmedian teeth similar to those of the fossil are common in many speciesof Tylochromis (Stiassny 1989) and the fossil lower pharyngeal jawmay well have belonged to a species of this genus (Stiassny perscomm) Tylochromis is a relatively basal cichlid lineage (Stiassny1991) of which most species are benthic macrophages (Stiassny 1989)Tylochromis is currently found in large rivers and open waters of WestAfrica and the Zaire Basin but is absent from Egypt (Stiassny 1989)If the Fayum specimen belonged to this genus it indicates that Tyloch-romis was once more widely distributed likely as part of a pan-Africanfish fauna which authors (eg Greenwood 1983) have suggested ex-

isted prior to the rifting in the Miocene which changed continentaldrainage patterns

The lack of other cichlid material from the Fayum collections maywell be attributed to collecting bias One would expect at least cichlidfin spines to be present as they are the most common isolated remainsof cichlids in other African fossil localities Future collections may pro-vide the material necessary to determine better the identity of the Fayumcichlid The fortuitous collection of the lower pharyngeal jaw providesthe first evidence that cichlids were present in Egypt in the earliestOligocene

Acknowledgements I am grateful to Dr Elwyn Simons for per-mission to study the Duke University Primate Center fishes from theFayum and I also thank D DeBlieux P Chatrath and E Simons fortheir help and hospitality during my visit to DUPC Thanks also go toS L Cumbaa and to R B Holmes for helpful comments on the man-uscript and to M L J Stiassny and L Taverne for helpful reviewsFunds for this work were provided by the Canadian Museum of Nature

LITERATURE CITED

Bown T M and M J Kraus 1988 Geology and paleoenvironmentof the Oligocene Jebel Qatrani Formation and adjacent rocks Fa-yum Depression Egypt US Geological Survey Professional Paper14521ndash60

Greenwood P H 1972 New fish fossils from the Pliocene of WadiNatrun Egypt Journal of Zoology London 168503ndash519

mdashmdashmdash 1973 Fish fossils from the Late Miocene of Tunisia Travauxde Geologie Tunisienne no 6(2) Notes du Service Geologique 3741ndash72

mdashmdashmdash 1983 The zoogeography of African freshwater fishes bioac-countancy or biogeography pp 179ndash199 in R W Sims J HPrice and P E S Whalley (eds) Evolution Time and Space TheEmergence of the Biosphere Systematics Association Special Vol-ume 23 Academic Press London and New York

Kappelman J 1992 The age of the Fayum primates as determined bypaleomagnetic reversal stratigraphy Journal of Human Evolution22495ndash503

mdashmdashmdash E L Simons and C C Swisher III 1992 New age determi-nations for the EocenendashOligocene boundary sediments in the Fa-yum Depression Northern Egypt Journal of Geology 100647ndash668

Kaufmann L S and K F Liem 1982 Fishes of the suborder Labroidei(Pisces Perciformes) phylogeny ecology and evolutionary sig-nificance Breviora Museum of Comparative Zoology 4721ndash19

Murray A M 2000 Eocene cichlid fishes from Tanzania East AfricaJournal of Vertebrate Paleontology 20651ndash664

mdashmdashmdash and K M Stewart 1999 A new species of tilapiine cichlidfrom the Pliocene Middle Awash Ethiopia Journal of VertebratePaleontology 19293ndash301

mdashmdashmdash and mdashmdashmdash In press Fish remains from the Late PlioceneChiwondo Beds Malawi Kaupia Darmstadter Beitrage zur Natur-geschichte

Nelson J S 1994 Fishes of the World 3rd ed John Wiley and SonsInc Toronto 600 pp

Peyer B 1928 Die Welse des agyptischen Alttertiars nebst einer kri-tischen Ubersicht uber alle fossilen Welse Abhandlungen der Bay-erischen Akademie der Wissenschaften Mathematisch-naturwis-senshaftliche Abteilung 32(3)1ndash61

Snoeks J 1994 The haplochromines (Teleostei Cichlidae) of LakeKivu (East Africa) a taxonomic revision with notes on their ecol-ogy Musee Royal de lrsquoAfrique Centrale Tervuren Annales Sci-ences Zoologiques 2701ndash221

Stewart K M 1997 Fossil fish from the Manonga Valley TanzaniaDescription paleoecology and biogeographic relationships pp333ndash349 in T Harrison (ed) Neogene Paleontology of the Man-onga Valley Tanzania Topics in Geobiology 14 Plenum PressNew York

Stiassny M L J 1989 A taxonomic revision of the African genusTylochromis (Labroidei Cichlidae) with notes on the anatomy andrelationships of the group Musee Royal de lrsquoAfrique Centrale Ter-vuren Annales Sciences Zoologiques 2581ndash161

mdashmdashmdash 1991 Phylogenetic intrarelationships of the family Cichlidaean overview pp 1ndash35 in M H A Keenleyside (ed) Cichlid Fish-es Behaviour Ecology and Evolution Chapman and Hall London

mdashmdashmdash and J S Jensen 1987 Labroid intrarelationships revisitedmorphological complexity key innovations and the study of com-

455NOTES

parative diversity Bulletin of the Museum of Comparative Zoology151269ndash319

Streelman J T and S A Karl 1997 Reconstructing labroid evolutionwith single-copy nuclear DNA Proceedings of the Royal Societyof London series B 2641011ndash1020

Stromer E 1916 Die Entdeckung und die Bedentung der Land undSusswasser bewohnenden Wirbeltiere im Tertiar und in der Kreide

Aegyptens Zeitschrift der Deutschen Geologischen Gesellschaft(Abhandlungen und Monatsberichte) 68397ndash425

Van Couvering J A H 1982 Fossil cichlid fish of Africa SpecialPapers in Palaeontology The Palaeontological Association London291ndash103

Received 9 May 2001 accepted 27 July 2001

454 JOURNAL OF VERTEBRATE PALEONTOLOGY VOL 22 NO 2 2002

FIGURE 1 Photographs of DUPC 4973 the lower pharyngeal jaw ofa cichlid fish A dorsal (occlusal) view B ventral view C lateral viewAnterior is towards the bottom in A and B and towards the right in CScale bar 5 5 mm

Only one subgroup of cichlids has been potentially characterized byfeatures of the lower pharyngeal jaw These are the tilapiine cichlidsin which Stiassny (1991) noted the lower pharyngeal jaw usually hastwo foramina one on either side of the median ventral suture and araised ridge on the anterodorsal aspect of the bone There are no foram-ina present on the Fayum specimen and there is no evidence of amedian ridge of bone on the dorsal surface of the jaw but the area inwhich the tilapiine cichlids have this ridge is mostly missing in theFayum specimen Although some individual tilapiines lack the foram-ina the robust dentition of the Fayum specimen in combination withthe lack of foramina stongly indicates that it is not a tilapiine (Stiassnypers comm)

Pharyngeal teeth can vary greatly within a species or genus (egStiassny 1989 Snoeks 1994) and therefore might not be useful toellucidate the relationships of the fossil jaw However hypertrophiedmedian teeth similar to those of the fossil are common in many speciesof Tylochromis (Stiassny 1989) and the fossil lower pharyngeal jawmay well have belonged to a species of this genus (Stiassny perscomm) Tylochromis is a relatively basal cichlid lineage (Stiassny1991) of which most species are benthic macrophages (Stiassny 1989)Tylochromis is currently found in large rivers and open waters of WestAfrica and the Zaire Basin but is absent from Egypt (Stiassny 1989)If the Fayum specimen belonged to this genus it indicates that Tyloch-romis was once more widely distributed likely as part of a pan-Africanfish fauna which authors (eg Greenwood 1983) have suggested ex-

isted prior to the rifting in the Miocene which changed continentaldrainage patterns

The lack of other cichlid material from the Fayum collections maywell be attributed to collecting bias One would expect at least cichlidfin spines to be present as they are the most common isolated remainsof cichlids in other African fossil localities Future collections may pro-vide the material necessary to determine better the identity of the Fayumcichlid The fortuitous collection of the lower pharyngeal jaw providesthe first evidence that cichlids were present in Egypt in the earliestOligocene

Acknowledgements I am grateful to Dr Elwyn Simons for per-mission to study the Duke University Primate Center fishes from theFayum and I also thank D DeBlieux P Chatrath and E Simons fortheir help and hospitality during my visit to DUPC Thanks also go toS L Cumbaa and to R B Holmes for helpful comments on the man-uscript and to M L J Stiassny and L Taverne for helpful reviewsFunds for this work were provided by the Canadian Museum of Nature

LITERATURE CITED

Bown T M and M J Kraus 1988 Geology and paleoenvironmentof the Oligocene Jebel Qatrani Formation and adjacent rocks Fa-yum Depression Egypt US Geological Survey Professional Paper14521ndash60

Greenwood P H 1972 New fish fossils from the Pliocene of WadiNatrun Egypt Journal of Zoology London 168503ndash519

mdashmdashmdash 1973 Fish fossils from the Late Miocene of Tunisia Travauxde Geologie Tunisienne no 6(2) Notes du Service Geologique 3741ndash72

mdashmdashmdash 1983 The zoogeography of African freshwater fishes bioac-countancy or biogeography pp 179ndash199 in R W Sims J HPrice and P E S Whalley (eds) Evolution Time and Space TheEmergence of the Biosphere Systematics Association Special Vol-ume 23 Academic Press London and New York

Kappelman J 1992 The age of the Fayum primates as determined bypaleomagnetic reversal stratigraphy Journal of Human Evolution22495ndash503

mdashmdashmdash E L Simons and C C Swisher III 1992 New age determi-nations for the EocenendashOligocene boundary sediments in the Fa-yum Depression Northern Egypt Journal of Geology 100647ndash668

Kaufmann L S and K F Liem 1982 Fishes of the suborder Labroidei(Pisces Perciformes) phylogeny ecology and evolutionary sig-nificance Breviora Museum of Comparative Zoology 4721ndash19

Murray A M 2000 Eocene cichlid fishes from Tanzania East AfricaJournal of Vertebrate Paleontology 20651ndash664

mdashmdashmdash and K M Stewart 1999 A new species of tilapiine cichlidfrom the Pliocene Middle Awash Ethiopia Journal of VertebratePaleontology 19293ndash301

mdashmdashmdash and mdashmdashmdash In press Fish remains from the Late PlioceneChiwondo Beds Malawi Kaupia Darmstadter Beitrage zur Natur-geschichte

Nelson J S 1994 Fishes of the World 3rd ed John Wiley and SonsInc Toronto 600 pp

Peyer B 1928 Die Welse des agyptischen Alttertiars nebst einer kri-tischen Ubersicht uber alle fossilen Welse Abhandlungen der Bay-erischen Akademie der Wissenschaften Mathematisch-naturwis-senshaftliche Abteilung 32(3)1ndash61

Snoeks J 1994 The haplochromines (Teleostei Cichlidae) of LakeKivu (East Africa) a taxonomic revision with notes on their ecol-ogy Musee Royal de lrsquoAfrique Centrale Tervuren Annales Sci-ences Zoologiques 2701ndash221

Stewart K M 1997 Fossil fish from the Manonga Valley TanzaniaDescription paleoecology and biogeographic relationships pp333ndash349 in T Harrison (ed) Neogene Paleontology of the Man-onga Valley Tanzania Topics in Geobiology 14 Plenum PressNew York

Stiassny M L J 1989 A taxonomic revision of the African genusTylochromis (Labroidei Cichlidae) with notes on the anatomy andrelationships of the group Musee Royal de lrsquoAfrique Centrale Ter-vuren Annales Sciences Zoologiques 2581ndash161

mdashmdashmdash 1991 Phylogenetic intrarelationships of the family Cichlidaean overview pp 1ndash35 in M H A Keenleyside (ed) Cichlid Fish-es Behaviour Ecology and Evolution Chapman and Hall London

mdashmdashmdash and J S Jensen 1987 Labroid intrarelationships revisitedmorphological complexity key innovations and the study of com-

455NOTES

parative diversity Bulletin of the Museum of Comparative Zoology151269ndash319

Streelman J T and S A Karl 1997 Reconstructing labroid evolutionwith single-copy nuclear DNA Proceedings of the Royal Societyof London series B 2641011ndash1020

Stromer E 1916 Die Entdeckung und die Bedentung der Land undSusswasser bewohnenden Wirbeltiere im Tertiar und in der Kreide

Aegyptens Zeitschrift der Deutschen Geologischen Gesellschaft(Abhandlungen und Monatsberichte) 68397ndash425

Van Couvering J A H 1982 Fossil cichlid fish of Africa SpecialPapers in Palaeontology The Palaeontological Association London291ndash103

Received 9 May 2001 accepted 27 July 2001

455NOTES

parative diversity Bulletin of the Museum of Comparative Zoology151269ndash319

Streelman J T and S A Karl 1997 Reconstructing labroid evolutionwith single-copy nuclear DNA Proceedings of the Royal Societyof London series B 2641011ndash1020

Stromer E 1916 Die Entdeckung und die Bedentung der Land undSusswasser bewohnenden Wirbeltiere im Tertiar und in der Kreide

Aegyptens Zeitschrift der Deutschen Geologischen Gesellschaft(Abhandlungen und Monatsberichte) 68397ndash425

Van Couvering J A H 1982 Fossil cichlid fish of Africa SpecialPapers in Palaeontology The Palaeontological Association London291ndash103

Received 9 May 2001 accepted 27 July 2001