Cretaceous dinosaurs of Africa: Examples from Cameroon and Malawi

16 Pages·1996·6.3 MB·

by  Louis L Jacobs

CRETACEOUS DINOSAURS OFAFRICA: EXAMPLES FROMCAMEROON
ANDMALAWI
LOUISL.JACOBS,DALEA. WINKLER&ELIZABETHM.GOMANI
Jacobs, L.L., Winkler, DA. &Gomani, E.M. 1996 12 20: Cretaceousdinosaurs ofAfrica:
ExamplesfromCameroonandMalawi.MemoirsoftheQueenslandMuseum39(3):595-610.
Brisbane. ISSN0079-8835.
AfricabecameprogressivelyisolatedduringthemiddleportionoftheCretaceousPeriodas
it rifted apart from other Gondwana continents and the southern Atlantic Ocean was
completed.Withinthisgeologicalcontext,whichcontrolstheoccurrenceanddistributionof
CretaceousfossillocalitiesovermostofAfrica,thereisconsiderablevarietyincomposition
and occurrence offossils. In the Koum Basin of Cameroon in western Africa, abundant
footprints of five morphotypes, but scrappy skeletal remains and teeth ofthe ornithopod
Ouranosaurus and other taxa are found. In the Karonga area of northern Malawi, in
southeastern Africa, more complete skeletal remains are known, including the sauropod
Malawisaurus, which shows affinity to South American titanosaurids, and anundescribed
sauropodtaxon.Thesemaydemonstratearangeofmorphological diversityinsub-Saharan
Cretaceous sauropods comparable to that found in South America. Cretaceous, Africa,
Sauropoda,palaeobiogeography, crocodfoa, stratigraphy.
Louis L Jacobs, Dale A. Winkler & Elizabeth M. Gomani, Department ofGeological
SciencesandShulerMuseumofPaleontology,SouthernMethodistUniversity,Dallas, Texas
75275 USA; 15August 1996.
Africais a vastcontinentwith a sporadic fossil theisolationofAfricabeganinthesouthbetween
record, remarkably good for some time intervals thecontinents.By the Late Albian to Cenoman-
insomeregions,yetdismallybadinothers,yield- ian the African terrestrial fauna may have been
ingadisjointedandsketchypictureofpastlifeon isolatedfromthatofSouthAmericabytheAtlan-
the continent. Our research into the African tic (Pittman etal., 1993). Thesegeographicchan-
Cretaceous is focused on sub-Saharan Africa, a ges would have precipitated climatic change by
largelytropicaltosubtropicalPrecambrianshield modifying oceanic and atmospheric currentsdis-
area, heavily vegetated for the most part, and tributing heatacross the Cretaceous world.
deeply weathered, often into fossil-destroying In the Early Cretaceous, volcanism in southern
lateritic soils. In this paper we are primarily Africa and the reactivation of the Precambrian
concerned with two areas of Lower Cretaceous East African mobile belt resulted in Cretaceous
outcrop: one in Cameroon and the other in fossildepositsin Malawi,andalongtheZambezi
Malawi. Both are associated with extensional River and its tributaries (Eby et al., 1995). Also
tectonicsalongreactivatedPrecambrianmobilebelts in the Early Cretaceous, as noted above, on the
(Mateeretal., 1992).Ourprimaryobjectiveinthis west side of the continent, South America and
paperistoprovideageneralcomparisonbetween Africa were rifting apart along a fault-rift-rift
the two; that is, between eastern and western triple junction (Popoff, 1988), completing the
African dinosaur faunas ofthe Early Cretaceous Atlantic Ocean by Cenomanian orearliertime.
using the Koum Basin, Cameroon, and the Thus, the Cretaceous fossil record is largely
DinosaurBeds ofKaronga,Malawi, asexamples controlled by the tectonic frameworkofthe con-
We
(Fig. 1). will also take this opportunity to tinent, which provided the geologic setting in
examine briefly African Cretaceous dinosaurs which fossil deposits formed. The chronology of
and theirrelationshiptothose ofSouth America. African Cretaceous localities has yet tobe docu-
Africa became isolated from Madagascar, mented in detail. Many identifications as
India, Australia and Antarctica during the Late presented in the literature are preliminary or
Jurassic (Pittman et al., 1993). One of the most based on incomplete material. Table 1 is a com-
profoundeventsaffectingthephysicalgeography pilation of published records of Cretaceous
of the Cretaceous world was the opening of the dinosaurs from Africa. This is provided as a
southern Atlantic Ocean by the rifting of South guide to published literature only, in recognition
America and Africa. Beginning in the earliest of the rather tentative nature of most of the
Cretaceous, tectonic rifting that culminated in entries.
596 MEMOIRS OFTHEQUEENSLANDMUSEUM
KOUM BASIN, CAMEROON
TheKoumBasinisanisolatedbasinassociated
withtheBenueTrough,amajorstructuralfeature
ofWest Africa (Figs 1, 2). The Benue Trough is
anaulacogen,thefailed armofthetriplejunction
that led to the completion ofthe Atlantic Ocean,
extending from the Gulf of Guinea through
Nigeria,thendividingintonorthernandsouthern
branches. The southern branch is called the Yola
Arm, which passes into Cameroon. While the
Koum Basin is not the only fossiliferous basin
associated with the Yola Arm (see also Brunetet
al., 1988;Dejaxetal., 1989;Michardetal., 1990),
itisofinterestherebecauseofthedinosaurfauna
it contains.
The most complete study of the Koum Basin
(also referred to as Mayo Rey Basin in Flynn et
al., 1987)anditsfaunatodateisthatofCongleton
(1990). The Koum Basin (Figs 2, 3) is an 80km
long half-graben oriented east-west, bounded to
the north by a fault, and filled with up to 3,000m
offluviatile,overbank,and lacustrineCretaceous FIG. 1. Location mapofKoumBasin, Cameroon and
sediments (Tillement, 1971). It is surrounded by the Dinosaur Beds, Mwakasyunguti area, Karonga,
Precambrian metamorphic rocks. Cretaceous Malawi. LakesChad andMalawiindicatedinblack.
sediments are exposed primarily along the Mayo
Rey, an east to west flowing tributary to the KB-8,KB-13),butnofootprints,areknownfrom
Benue River. the Gres de Gaba Member. Congleton et al.
(1992) present a section measured at locality
Congleton (1990) referred to the Cretaceous
sediments as the Koum Formation, in which he KB-6, the most productive bone locality. The
recognised two areally restricted and well- base of the locality is coarse sand containing
defined members.TheMbissirriMemberiscom- fragmentary scattered bones and teeth repre-
posed of reddish fine-grained silty mudstones, senting predominantly, in order of abundance,
clay shales, thin limestones and sandstones. iguanodontian, theropod and sauropodomorph
There appear to be cyclical repetitions of cross- dinosaurs. One tooth was identified as
bedded sandstonesand thickermudstoneswithin thyreophoran(?); we consider that identification
a sequence generally coarsening upwards. Con- dubious and the specimen possibly confused
gleton (1990) suggested thatthe Mbissirri Mem- with a crocodilian. The iguanodontian teeth
ber represented lacustrine and aggraded resemble those of Ouranosaurus. The section
meandering stream sediments within a fine- finesupwardsand small bones,representingpar-
grained meander belt. Carbonised plant frag- ticularly anurans and the crocodyliform
ments, conchostracans, turtlecarapacefragments Araripesuchus, but also mammals (Brunetet al.,
anddinosaurfootprintlocalities (designated KB- 1990,Jacobsetal., 1988), areconcentratedinthe
3, KB-17, KB-18, KB-23 in Fig. 3) have been lower portion ofa mudstone, at the top ofwhich
found in the Mbissirri Member. a calcareous palaeosol is developed. Insect trace
The Mbissirri Member is overlain along the fossilsresembling hymenopteran larval cases are
northern margin of the basin by the coarse- found in the palaeosol. The sequence is suc-
grained Gres de Gaba Member. The contact is ceeded by a coarse sandstone representing the
A
gradational. The sediments ofthe Gres de Gaba initiation ofthe nextfluvial cycle. neural arch
Member are medium to coarse-grained cross- and neural spine attributed to the region of the
bedded arkosic sandstones, conglomerates, and sixteenthdorsal vertebraofOuranosaurus(based
interbedded mudstones and palaeosols. Con- on height ofspine and position ofthe transverse
gleton(1990)interpretedtheGresdeGabaMem- processes) wasfoundinconglomeraticsandstone
ber as representing a coarsegrained, braided at locality KB-13, overlying KB-6 by ap-
fluvial system. Bone-bearing localities (KB-6, proximately 5 meters.
CRETACEOUSDINOSAURS OFAFRICA 597
CHAD
KOUM BASIN
CENTRAL
;
\ AFRICAN
REPUBLIC
'.
• Yaounde
FIG. 2. DistributionofCretaceousandyoungersediments(stippledpattern) intheBenuetrough (redrawnfrom
Allix, 1983).
Congleton et al. (1992) suggested that faunas Dinosaur footprints are relatively abundant in
of the Koum Basin were correlative with the the Koum Basin. Congleton (1990) recognized
localityofGadoufaoua,Niger,basedonthecom- five morphotypes of tracks corresponding to
mon occurrence of Araripesuchus and theropod, ornithopod and sauropod, consistent
Ouranosaurus.TheageofGadoufaouaisusually with incompleteskeletalremainsfromelsewhere
considered Aptian (Taquet, 1976). Colin et al. in the basin. The most prolific trackway site is
(1992) report the ostracode Cypridea minuscula KB-17 in the Mbissirri Member, where tracks
fromthe Koum Basin (locality KB-24, Mbissirri occur in four successive sandstone strata. Small
Member). This genus was originally described theropod prints are the most abundant mor-
fromthe Candeias Formation, Reconcavo Basin, photype. Taken together, the trackways are
Brazil. The Candeias Formation is placed within directed north-northeast or south-southwestcon-
the Rio da Serra local stage (Mouraetal., 1994), sistently, suggesting that the pathways remained
which ranges from the lower Berriasian to the constant over the flooding events that deposited
lowerHauterivianstages(Ponte, 1994).Brunetet the track-bearing strata and thata consistentbar-
al. (1988) estimated the age ofthe nearby Mayo rierguided the movements ofthe dinosaurs.
Oulo Lere Basin to be approximately around the A considerable amount of variation in stride
Hauterivian-Barremian transition based on length and other indicators of relative speed or
plants, particularly the palynomorph inferred behavior is reported by Congleton
Dicheiropollis etruscus. A similar age is sug- (1990). Interpreted gaits include walking, trot-
gested for the Babouri-Figil Basin, which also ting, sprinting, acceleration, deceleration and
contains dinosaur tracks, for the same reason hobbling.Themajorityofthetrackmakersappear
(Dejax et al., 1989). It appears likely that the tohavebeen walking, however,basedonrelative
Koum Basin is Early Cretaceous in age, no stridelengthandpaceangle.Smallertrackmakers
youngerthan Aptian, butperhaps older. appear relatively more energetic than larger
598 MEMOIRS OFTHEQUEENSLANDMUSEUM
+ * * ToGaroua + K +
Tchollire SL1 * * . / ToMadingrin
Ntham^.11V-."—Ma*n*a?n*gia
X
**p 3 4 --\Mayo_?S^^
((19/
++*.++
+ + * T + + '.HIT .*_ 1 ***j**Z **++ + +/ +
+ *+ * % + • * * * * * / + + + 04 * * V + * V,
/f / * 1 ^
)' T)o) Touboro N
A
Lower GresdeGaba Member Koum
Cretaceous Mbissirri Member Fm. :%v,:v;-qh
Precambrian Metamorphicbasement
• 4 KBfossillocality 10 20km
£- Fault
FIG. 3. Geologicalmapofthe Koum Basin, northern Cameroon(redrawnfromCongleton, 1990).
trackmakers, as interpreted from inferred stride One fault trends north-south, cutting across al-
rates. most the entire study area. It juxtaposes sedi-
ments of the upper Dinosaur Beds against the
KARONGA, MALAWI lower Dinosaur Beds and the Precambrian base-
ment. Drag on this fault results in southwesterly
The Dinosaur Beds of northern Malawi are dips forthe upperpartofthe DinosaurBeds. The
locatedalongtheSitweRiverintheMwakasyun-
second clearly visible fault cuts across Cretaceous
guti area of Karonga District. Malawi is a long, and Cenozoic sediments, juxtaposing the entire
narrow country locatedinthe southern portionof
package against Precambrian basement.
the East African Rift. Karonga is the north- Dixey (1928; see also Gomani, 1993) divided
eaprpnrmooxsitmpartoevliyn7ce0kanmdsMowuathkwaessytunofguKtairoisnglaocDaitse-d the Dinosaur Beds into an upper and a lower
memberbased mainly on color. The lowermem-
tarnictoHveeardvqiueawrteorfs.prJeavcioobussetpaall.ae(o1n9t9o2l)ogpircoavlidreed- ber is unfossiliferous red and purple mud and
calcite-cemented sandstone, locally con-
search in Malawi.
The Sitwe River near Mwakasyunguti flows glomeratic with some mottling and dessication
throughanorth-southtrendinghalfgraben,paral- cracks.Theuppermemberiscomposedprimarily
leling the Malawi Rift System (Kaufulu, 1989; of fossiliferous alternating red and white
Tiercelin et al., 1988) and bordered by crossbedded fluvial sandstones deposited along
Precambrian metamorphic basement. Three braided streams. At least two distinct modes of
sedimentary formations are exposed in the half bonepreservationarefoundintheDinosaurBeds.
graben (Fig. 4): the DinosaurBeds are deposited Nearly complete and articulated notosuchid
on thebasementand are unconformablyoverlain crocodyliforms (Clark et al., 1989; Gomani,
by the Plio-Pleistocene Chiwondo Beds, which 1993, inpress)are found within burrowsinaban-
are in turn unconformably overlain by the Pleis- donedchannelsediments. Amorediversesuiteof
tocene Chitemwe Beds. dinosaurs and othertaxa occur as isolated bones,
The Dinosaur Beds are commonly tilted to the associated clusters, or articulated elements in
northeast with dips ranging from 14-25° north- course poorly-sorted sandstone (Gomani, 1993).
east. They are cut by two obvious faults (Fig. 4). Plantmacrofossilsarerarewithonlytwodiaspores
CRETACEOUS DINOSAURS OFAFRICA 599
skeletons, which apparently
died in burrows (Gomani, in
press). Ithasalongandflatjaw
articulation surface and a
heterodont dentition with mul-
ticusped teeth (Clark et al.,
1989; Gomani, in press) that
appear to be similar to Can-
didodon from Brazil (Carvalho
& Campos, 1988; Carvalho,
1994) and Chiinaerasuchus
from China (Wu et al., 1995).
Although distinct, a close
phylogenetic relationship of
theMalawinotosuchid to Can-
didodon and Chimaerasuchus
appears likely, but cannot be
tested until better material of
thesegenerais found(Gomani,
in press). The cms and tarsal
bone articulations of the
Malawi notosuchidarevertical
and the distal condyles of the
femur are posteriorly directed.
Theseindicateanerectposture.
The ventral position ofthe oc-
cipital condyle and foramen
magnumindicatesthatthehead
was held perpendicular to the
neck (Gomani, in press).
Based on field identifica-
FI(Gr.ed4r.aGwenolforgoimcaGlommaanpi,of19M9w3a)k.asyunguti area, Karonga District, Malawi tMiaolnsa,wiit wdaisnossuagugrestfeaduntahatcotnh-e
sistsofatleastfivetaxainclud-
havingbeenrecovered(Jacobs, 1990),andpollen
is not preserved. The vertebrate fauna indicates ing a titanosaurid, a diplodocid, two morphs of
theropods and a stegosaur. However, examina-
an Early Cretaceous age (Jacobs etal., 1990).
tion ofArgentinean dinosaur specimens and fur-
The vertebrate fauna, including fish (but not ther preparation of the Malawian material
lungfish), anurans, turtles, crocodyliforms and necessitate re-evaluation. There are at least two
dinosaurs (Jacobs et al., 1990, 1992; Gomani, species of sauropods, one of which is
1993), has been collected from localities desig-
rneaptreedseasnteCdD-bIytotwCoD-sk1u7ll(Ffigr.ag4m)e.ntAsn:uroannes haarse Mala.,la1w9i9s0,au1r9u9s2,dix1e9y9i3;(HGaoumgahntio,n,1199932)8,;Jtahecoobtsheert
rugose dermal bones and the other one has no of which is undescribed and has 'pencil-like'
sculpturing (Jacobs et al., 1990). The teeth. At least two species of theropods are
crocodyliformsincludean interestingnotosuchid present,basedonteeth(Jacobsetal., 1990, 1992).
(Gomani, in press), aff. Araripesuchus sp., and The most abundant elements belong to Malawi-
teethofanunidentifiedtaxon.Aff.Araripesuchus saurus, a titanosaurid.
is represented by isolated ziphodont teeth which Malawisaurus is a titanosauridbecause ithas a
are indistinguishable from specimens from transversely expanded ischium and strongly
Cameroon (Congleton, 1990). The latter procoelous anterior caudal vertebrae, derived
resemble the type of Araripesuchus wegeneri characters that are considered diagnostic for the
from Niger (Buffetaut, 1981), which Kellner Titanosauridae, or possibly a more inclusive
(1994) argues may be generically distinct from monophyletic group containing Malawisaurus.
the genotypic South American species. The Titanosaurids are known to have dermal armor
&
notosuchid species is represented by complete (Deperet, 1896; Bonaparte Powell, 1980).
600 MEMOIRS OFTHEQUEENSLANDMUSEUM
Malawisaurus lacks direct evidence of dermal 182 are closer together than in Mal-181. The
armor,butcalcitepseudomorphs shapedlikeder- undivided neural spine is high and inclined
mal armor were found associated with the bones caudally inMai-181,butitisverticalinMai-182.
in the same quarry (Jacobs et al., 1993). Supradiapophysial laminae in Mal-181 andMal-
OnecervicalvertebrareferredtoMalawisaurus 182arewell-developed.Deeplateralexcavations
(Mai-180, Fig. 5A) has a low neural spine that is and high prespinal laminae also occur in Salta-
not bifurcated. The prezygapophyses extend saurus loricatus, Andesaurus delgadoi and
10cm beyond theanteriorend ofthecentrumbut Argyrosaurus superbus from Argentina
the postzygapophyses do not extend posteriorly (Bonaparte& Powell, 1980; Calvo& Bonaparte,
beyond the centrum. The centrum lacks 1991). In Saltasaurus, caudally inclined neural
pleurocentral cavities. The cervical ribs are spinesoccurinmoreanteriordorsalvertebraeand
coosifiedto thecentrumandhavecranial proces- vertical neural spines occur in posterior dorsal
ses that terminate at the anterior limit of the vertebrae (Powell, 1986). Based on comparison
centrum. The shaftsoftheribsextend beyond the with these taxa, Mal-182 probably is more
centrum posteriorly. In Saltasaurus loricatus posterior in the vertebral column of
(PVL 4017-139) of Argentina and in cf. Malawisaurus than Mal-181.
Titanosaurus from Brazil (Powell, 1986), the Caudal vertebrae of Malawisaurus are
prezygapophyses do not extend beyond the described by Jacobs et al. (1993). The vertebrae
centrum while the postzygapophyses do extend progressfromprocoeloustogentlyamphicoelous
beyondthecentrum. Inaddition,Saltasaurusand posteriorly. The anterior caudals are strongly
cf. Titanosaurus cervical vertebrae have procoelous, the prezygapophyses extend slightly
pleurocentral cavities on the centra. In anterior beyond the centrum as in Titanosaurus sp. from
cervicalsofSaltasaurusneural spines do not rise Argentina (Powell, 1986) andAlamosaurusfrom
above the neural arches while in posterior cervi- North America (Gilmore, 1946). However,
cals low neural spines rise above the neural ar- Alamosaurusand Titanosaurus are more derived
ches. BasedoncomparisonwithSaltasaurus,this because all their posterior caudal vertebrae are
vertebra ofMalawisaurus (Mai-180) is probably procoelous.Malawisaurusalsoshareslowcaudal
posterior to the fourth cervical in position. neural spines with Andesaurus and derived
Dorsal vertebrae attributed to Malawisaurus titanosaurids. Malawisaurus is distinct from
(Mai-181, and Mai-182, Figs 5B-D) indicate no Andesaurus and Epachthosaurus because these
evidence of hyposphene-hypantrum articular genera have hyposphene-hypantrum articular
&
surfaces. The centra are opisthocoelous and surfacesondorsal vertebrae(Calvo Bonaparte,
pleurocoels are anteriorly restricted. The 1991)thatareabsentinMalawisaurus.Allcaudal
transverse processes of Mal-181 are wide and vertebraeofEpachthosaurus are procoelous.
slightly inclined dorsally. The broad-based, un- Isolated teeth similar to those associated with
divided neural spine has elongate anterolateral titanosaurids from Argentina (Huene, 1929 PI. 1.
depressions that are at the same level as the post- Figs 12-13; Powell, 1986), Brazil (Kellner, this
zygapophyses. A well-developed thin prespinal volume) and to those associated with
laminaoccursatthe anteriorbase.Thepostspinal Alamosaurus from North America (Kues et al.,
lamina is thickerthan the prespinal lamina. 1980; Lucas&Hunt, 1989)occurintheDinosaur
The base ofthe undivided neural spine in Mal- Beds. These teeth are slender and conical.
182 is narrower than in Mal-181. The prespinal Presence of relatively long slender and conical
lamina is well-developed. In anterior dorsals (peglike)teeth isoneofthediagnostic featuresof
(dorsals 1-4) of sauropods the parapophyses are Titanosauridae and Diplodocidae (Mcintosh,
located on the centra while on the posterior 1990;TitanosauroideaandDiplodocoideaofUp-
dorsals, theparapophysesarehighonthecentro- church, 1995). Thus, the slender teeth in the
diapophysial lamina that extends from the DinosaurBedsmaybetitanosauridordiplodocid.
diapophysis(Mcintosh, 1990).Mal-181 andMal- ThepresenceofdiplodocidsintheDinosaurBeds
182 are not anterior dorsals because the centra is suggested by the derived features of an un-
lack parapophyses. In Epachthosaurus, the described mandible. It has a short tooth row and
parapophyses become progressively higher the ramus turns at a sharp angle towards the
posteriorly on dorsals. The transverse processes symphysis where the dorsal margin ofthe man-
of Mai-182 are broken, thus the height of the dible flares outward. These characters are also
parapophysesandrelativevertebral positioncan- present in South American Antarctosaurus
notbedetermined. The prezygapophyses in Mai- (Huene, 1929; Huene & Matley, 1833; Powell,
CRETACEOUS DINOSAURS OFAFRICA 601
Diplodocoidea of Upchurch,
1995), it is clear that the mor-
phological diversity of both
South American and African
saurpods may be greater than
we previously anticipated.
A pelvis from CD-10 is a
titanosaurid as suggested by
the pelvis of Epachthosaurus
and Saltasaurus. The anterior
blade of the ilium of these
titanosaurids is curved
anterolateral^, a feature that
may be derived for this group
of sauropods. Further descrip-
tion ofthe pelvis from Malawi
awaits complete preparation.
DISCUSSIONAND
CONCLUSION
Dinosaurs ofCretaceous age
in Africaarewidelydistributed
geographically (Table 1). The
data used in thecompilation of
Table were derived from
1
Broom (1904), Haughton
&
(1928), Dixey Smith (1929),
Dixey(1937,1939),Greigertet
aL (1954), Lavocat (1954),
Lapparent(1960), Said(1962),
Broin et al. (1971,1974), Ken-
&
nedy Klinger(1972),Russell
et al. (1976), McLachlan &
McMillan (1976), Taquet
(1976,1982,1984),El-Khashab
(1977), Monbaron (1978),
Klitzsch et al. (1979),
Pentel'kov & Voronovsky
&
(1979), Sues Taquet (1979),
Dutuit & Ouazzou (1980),
Sues(1980),Galton&Coombs
(1981), Rich et al. (1983),
Cooper (1985), Kent &
Gradstein (1985, 1986), Wil-
FIvlGait.eewr5;a.lsVacenarldteep=bors1at0eercoimfo.rMBva,ileaCww,,iDsr,aesudporerucssta.ilvsAe,loyfm)M.iadDld,alweMiacsle-ar1vui8rc2ua,sl,l(eMBfat,lCl-a,t1Me8ra0all,-v1lie8fe1tw,l.artBie-grhaDlt alli.am(1&98S7a)v,agHean(1d9f8o6r)d,F(l1y9n8n7)e,t
scales=3cm. Kennedy et al. (1987), Mateer
(1987), Shrank (1987),
1986). Those authors considerAntarctosaurus a Bouazizetal.(1988),Brunetetal.(1988),Carroll
titanosaurid, but others have suggested (1988), Buffetaut (1989a, 1989b), Dejax et al.
diplodocid or diplodocoid relationships (Jacobs (1989), Jacobs et al. (1989, 1990, 1992, 1993),
et aL, 1993; Hunt et aL, 1994; Upchurch, 1994, Colin&Jacobs(1990),Congleton(1990),Jacobs
1995). While these are given as characters of (1990), Klitzsch & Squyres (1990), Lefranc &
Diplodocidae (Berman & Mcintosh, 1978; Guiraud (1990), Weishampel (1990), Wycisk
602 MEMOIRS OFTHEQUEENSLAND MUSEUM
(1990), Moody & Sutcliffe (1991), Colin et al. amphicoelous posterior caudal vertebrae may
(1992), Congleton et al. (1992), Matcer et al. be fairly common among titanosaurids and taxa
(1992), Werner (1993a, 1993b), Wescott et al. cannot be excluded from the group because of
&
(1993), Krause Dodson, (1994); Sereno et al. amphicoelous posteriorcaudals.
&
(1994, 1996), Rauhut Werner (1995), Forster Diplodocids in the Cretaceous of Africa are
(1996), Sampson et al. (1996), Krause et al. (in reported from the Cenomanian of Morocco and
press), and the references therein. The most the Albian of Niger, Algeria and Morocco
widely distributed sauropods in Africa are (Lavocat, 1954; Lapparent, 1960; Taquet, 1976).
titanosaurids. This is important for palaeo- These are represented by dorsal vertebrae,
biogeographical comparison between Africa and
humerus, sacrum and teeth of Rebbachisaurus
South Americabecausetitanosaurids are alsothe and isolated pencil-like teeth (not figured) ofan
mostwidely distributedgeographically and most unnamed taxon from Niger (Taquet, 1976). The
n1u92m9e;roHusuesnaeuro&poMdastlineyS,ou1t9h33A;meBroincaapa(Hruteene&, identification of the unnamed taxon is based on
comparison with Dicraeosaurus teeth from the
Powell, 1980; Powell, 1986; Weishampel, 1990). Kimmeridgian of Tanzania. Because some pen-
In Africa, Cretaceous titanosaurids are reported
cil-like teeth are referred to titanosaurids, the
from the Campani&an of Madagascar (Russell et teeth from Niger require further study for confi-
al., 1976; Sues Taquet, 1979; Sues, 1980; dent assignment to taxon. In the Cretaceous of
Forster, 1996;Sampsonetal., 19%; Krauseetal., SouthAmerica,diplodocids(diplodocoidsofUp-
in press), the Senonian ofSudan (Werner, 1993a, church, 1995)arerepresentedbyRebbachisaurus
1993b), the&Turonian-Santonian of Kenya (recently reported by Calvo & Salgado, 1995, in
(Arambourg Wolff, 1969; Weishampel, 1990; a paper we have not yet had the opportunity to
Westcott et al., 1993), the Cenomanian ofEgypt evaluate) and Amargasaurus (Salgado &
(Stromer, 1932), theAlbian ofNiger(Lapparent, Bonaparte, 1991). Amargasaurus is most closely
1960), the Aptian ofMalawi (Jacobsetal., 1992, related to the Late Jurassic Dicraeosaurus from
1993). Tendaguru, Tanzania (Upchurch, 1995). The
Titanosaurid sauropods are clearly important African titanosaurid Malawisaurus is more
elements in the Cretaceous fauna of both South derived than Janenschia from Tendaguru and
AmericaandAfrica.Titanosaurids are consider- moresimilartoSouthAmericanAndesaurus.The
ed to include Aegyptosaurus, Aeolosaurus, undescribed jaw from the Dinosaur Beds of
Alamosaurus* Andesaurus Antarctosaurus, Malawi may be diplodocid but the phylogenetic
^
Argentinosaurus, Argyrosaurus, Epachthosaurus, relationshipstoothersauropodswill bepresented
Hypselosaurus, Janenschia, Laplatasaurus, elsewhere.
Macrurosaurus, Magyarosaurus, Malamsaurus,
Early Cretaceous sediments and fauna from
Saltasaurus, Titanosaurus and questionably Cameroon and Malawi are depositionally dif-
Campyiodoniscus. The mostdiagnosticand most ferent and taxonomicaily distinct. In Cameroon,
commonly used synapomorphy of titanosaurids
fossils occur in lacustrine, meanderbelt channel,
is strongly procoelous caudal vertebrae. Having overbank and braided stream deposits, while in
allcaudalvertebraeprocoelousisderivedrelative Malawi dinosaur fossils occur predominantly in
to having posteriorcaudals amphicoelous.
course-grained,braidedfluvialsedimentslacking
Malawisaurus has gently amphicoelous finegrained overbank deposits. Footprints occur
posterior caudals. This feature is also seen in in Cameroon but not Malawi. Bones are more
Janenschia from Tanzania (Janensch, 1922; complete in Malawi. Cameroon appears to have
1961), Aeolosaurus rionegrinus from Argentina a more diverse total fauna than Malawi. In
(Powell, 1986; 1987) and Macrurosaurus from Cameroon, the ornithopod Ouranosaurus is
England (Seeley, 1876). No anteriorcaudal ver- present while Malawi has no ornithopods. In
tebrae are known for Andesaurus (Calvo & Malawi, sauropods are the best represented ele-
Bonaparte, 1991).Theposteriorcaudal (Calvo& ments, while they are rare in Cameroon. In
Bonaparte, 1991, Figs 4A-C) of the latter is neither area do we have a reasonably complete
described as amphiplatyan. Huene & Matley understandingofthefaunabecauseofinadequate
(1933) described an amphiplatyan posterior sampling, but both contribute to the palaeon-
caudal and associated it with Titanosaurus tological baseline for Africa. Compared to other
indicus. The use ofthe terms gently amphicoelous African localities, the Koum Basin appears most
ascompared to amphiplatyan in this case may be similar to Gadoufaoua, Niger, which is close in
a distinction without a difference. Having gently proximity andprobably in age; butneitherKoum
CRETACEOUS DINOSAURSOFAFRICA 603
TABLE 1. CretaceousdinosaursofAfrica.
TAXON STAGE LOCALITY(ROCKUNIT) REFERENCE
Theropoda
Elaphrosaurus Cenomanian MarsaMatruh,Egypt(BaharijaFm) L1a9p7p7arent, 1960;Said, 1962;El-Khashab,
Album Kasr-es-Souk,Morocco(TeganaFm) Lapparent, 1960;Monbaron, 1978
Afrovenator HBaauitreermiivainan- SouthernSahara,Niger Serenoetal., 1994
Majungasaurus Campanian- MarsaMatruth,Egypt(PhosphaticBeds) Lapparent, 1960;Said, 1962;El-Khashab,
Maastrichtian 1977
Campanian M(MaajeuvnagraaDniostFrimc)t,Madagascar SRuusesse,ll19e8t0;al.F,os1t9e7r6,;1S9u9e6s;&SaTmapqsueotn,et19a7l.9,;
1996;Krauseetal.,inpress
Bahariasaurus TSuarnotnoiniaann- Agadez,Niger(InBecetenFm) Greigertetal., 1954;Broinetal., 1974
MarsaMatruh,Egypt(BaharijaFm); Greigertetal., 1954;Lapparent, 1960;
Cenomanian Tahoua,Niger(FarakFm);Northern Said, 1962;Taquet, 1976;El-Khashab,
Province,Sudan(WadiMilkFm) 1977;Werner, 1993a
Albian Agadez,Niger(ContinentalIntercalate) Lapparent, 1960
MarsaMatruh,Egypt(BaharijaFm);North- Lavocat, 1954;Lapparent, 1960;Said,
Carcharodonto-
Cenomanian ernProvince,Sudan,(WadiMilkFm); Kern 1962;El-Khashab, 1977;Werner, 1993a;
saurus
Kem,Morocco,(KernKernBeds) Serenoetal., 1996
CAlebnioamna-nian HReadmmBeaddsa)duGuir,Morocco(Continental Buffetaut, 1989a, 1989b
Tamenghest,Wargla,&Adrar,Algeria;
Agadez,Niger(Continental Intercalaire); Lapparent, 1960;Monbaron, 1978;
Albian Kasr-es-Souk,Morocco(TeganaFm); BouazizetaL, 1988
Gharyan,Libya(ContinentalIntercalaire)
Medenine,Tunisia(CheniniFm)
Aptian Medenine,Tunisia(CheniniFm) Bouazizetal., 1988
Deltadromeus Cenomanian KemKem,Morocco,(KemKemBeds) Serenoetal., 1996
Spinosaurus Turonian- RiftValleyProvince,Kenya(Turkana Weishampel, 1990;Wescottetal., 1993
Santonian Grits)
Cenomanian MarsaMatruh,Egypt(BaharijaFm) Lapparent,1960;Said,1962;E-Khashab,1977
CAlebnioamna-nian HReadmmBeaddsa)duGuir,Morocco(Continental Buffetaut, 1989a, 1989b
Albian Medenine,Tunisia(CheniniFm) Bouazizetal., 1988;Weishampel, 1990
Aptian Gadoufaoa,Niger(ElrhazFm) Taquet, 1976; 1982; 1984
BApatriraenmian- MayoDjarendi,Cameroon(KoumBasin) CCoonlgilneettoanl.,,11999902;Congletonetal., 1992;
?Spinosaurid Aptian Agadez,Niger(ElrhazFm) Lapparent, 1960
indet.
ABpatriraenmian- MayoDjarendi,Cameroon(KoumBasin) Congleton 1990;Colinetal., 1992
Dromaeosaurid Cenomanian NorthernProvince,Sudan(WadiMilkFm) Rauhut&Werner, 1995
Tuanhnddeerisoncpdreoitd.baed Campanian MM(aMarajseuavnagMraaatDnrioushtFr,imcE)tg,yMpatd(aNguabsicaanrsandstone); S1a9i9d6,;1S9a6m2;psWoenisehtaalm.p,e1l9,961990;Forster,
Turonian- RiftValleyProvince, Kenya(Turkana Weishampel, 1990;Wescottetal., 1993
Santonian Grits)
WarglaandAdrar,Algeria(Continental
Albian IInntteerrccaallaaiirree));;GAhgaardyeazn,,NLiigbeyra(C(oCnotnitniennetnatlal Lapparent, 1960;Broinetal., 1971
Intercalaire);Meoenini,Tunisia(CheniniFm)
Aptian Agadez,Niger(ElrhazFm) Lapparent, 1960;Broinetal., 1974
BApatriraenmian- MayoDjarendi,Cameroon(KoumBasin) Congleton, 1990;Colinetal., 1992
Barremian CRaipveerPrFovmi)nce,SouthAfrica(Sundays Richetal., 1983;Weishampel, 1990
604 MEMOIRS OFTHEQUEENSLANDMUSEUM
TABLE
\{cont.)
TAXON STAGE LOCALITY(ROCKUNIT) REFERENCE
Tithonian- CapeProvince,SouthAfrica(Upper
Hauterivian Kirkwood;EnonFm) Richetal., 1983;Mateer, 1987
Theropod
Maastrichtian Agadir,Morocco(Unnamedunit) Weishampel, 1990
footprints
Cenomanian Laghout,Algeria(Unnamedunit) Weishampel, 1990
Barremian- MayoDjarendi,Cameroon(KoumBasin) Flynnetal., 1989;Congleton, 1990;
Aptian Congletonetal., 1992;Colinetal., 1992
Sauropoda-Diplodocidae
Dcfi.craeosaurus Cenomanian MarsaMatruhTEgypt(BaharijaFm) L1a9p7p7arent, 1960;Said, 1962;El-Khashab,
Rebbachisaurus Cenomanian KemKem,Morocco,(KemKemBeds) Lavocat, 1954;Serenoetal., 1996
Adrar,WarelaandTamenghest,Algeria
(ContinentalIntercalate);Agadez,Niger Greigertetal., 1954;Lavocat, 1954;
Albian (ContinentalIntercalate);Tahoua,Niger Lapparent, 1960;Taquet, 1976;
(FarakFm);Kasr-es-Souk,Morocco(Tegana Monbaron, 1978
Fm);Medenini,Tunisia(CheniniFm)
Algoasaurus Tithonian- CapeProvince,SouthAfrica(Upper Broom, 1904;McLachlan&McMillan,
Hauterivian KirkwoodFm) 1976
Dainpdluodnodceisdcriindbeetd Aptian Agadez,Niger(ElrhazFm) Lapparent, 1960;Taquet, 1976, 1982, 1984
Titanosauridae
Titanosaurus Campanian M(MaajeuvnagraaDniostFrimc)t,Madagascar S1u9e96s;&SaTamqpuseotn,e1t97al9.;, S1u9e9s6,;1K9r8a0u;seFoertstale.r,,
inpress
TSuarnotnoinaina-n GRriifttsV)alleyProvince,Kenya(Turkana Weishampel, 1990;Wescottetal., 1993
Aegyptosaurus Cenomanian MarsaMatruh,Egypt(BaharijaFm); Greigertetal., 1954;Lapparent, 1960;
Tahoua,Niger(FarakFm) Said, 1962;El-Khashab, 1977
Albian Agadez,Niger(ContinentalIntercalate) Greigertetal., 1954;Lapparent, 1960;
Taquet, 1976
Malawisaurus Aptian Karonga,Malawi(DinosaurBeds) Hauehton, 1928;Jacobsetal., 1990, 1992,
1993
Titanosaurid
Maastrichtian Agadir,Morocco(Unnamedunit) Weishampel, 1990
indet.
Campanian MajungaDistrict,Madagascar Suez&Taquet, 1979;Sues, 1980;Foister,
(MaevaranoFm) 1996
Santonian Natal,SouthAfrica(Unnamedunit) Kennedyetal., 1987
Turonian-
Santonian Agadez,Niger(Unnamedunit); Broinetal., 1974
Cenomanian NorthernProvince,Sudan(WadiMilkFm) RScahurhauntk,&1W9e8r7n;eWre,rn1e9r9,51993a; 1993b;
Aptian Agadez,Niger(InBecetenFm); Greigertetal., 1954;Broinetal., 1974;
Gadoufaoa,Niger(ElrhazFm) Taquet, 1976, 1982
Tithonian- CapeProvince,SouthAfrica(Upper
Hauterivian KirkwoodFm) Forster, 1996
Brachiosauridae
Brachiosaurus Albian WarglaandAdrar,Algeria(Continental Lapparent, 1960
Intercalate)
IPleurocoelus Albian Agadez,Niger(ContinentalIntercalate) Lapparent, 1960
Tithonian- CapeProvince,SouthAfrica(Upper McLachlan&McMillan, 1976;Richet
Hauterivian KirkwoodFm) al., 1983
Brachiosaurid Tithonian- CapeProvince,SouthAfrica(Upper
indet. Hauterivian KirkwoodFm) Forster, 1996
Camarasauridae
Camarasaurid Tithonian- CapeProvince,SouthAfrica(Upper
indet. Hauterivian KirkwoodFm) Richetal., 1983