Proceedings of the Zoological Institute RAS
Vol. 316, No. 2, 2012, рр. 139–147

УДК 568.19

THE FORGOTTEN DINOSAURS OF ZHETYSU(EASTERN KAZAKHSTAN; LATE CRETACEOUS)
A.O. Averianov1*, H.-D. Sues2 and P.A. Tleuberdina31

Zoological Institute of the Russian Academy of Sciences, Universitetskaya Emb. 1, 199034 Saint Petersburg, Russia;
Department of Paleontology, Geological Faculty, Saint Petersburg State University, 16 liniya VO 29, 199178
Saint Petersburg, Russia; e-mail: dzharakuduk@mail.ru
2

Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, MRC 121, P.O. Box 37012,
Washington, DC 20013-7012, U.S.A.; e-mail: suesh@si.edu
3

Institute of Zoology, Pr. Al-Farabi 93, Akademgorodok, 050060 Almaty, Kazakhstan; e-mail: p.tleuberdina@mail.ru
ABSTRACTThe Late Cretaceous dinosaur-bearing localities discovered in the Ili River Basin in the foothills of Dzhungar
Alatau, in the center of the historical region Zhetysu (Semirechie), in 1925–1927 are among the first occurrences
for dinosaurs discovered in Asia. Preliminary identifications of dinosaurian remains from the Zhetysu localities,
reviewed by Nesov (1995a), included Sauropoda, Tyrannosauridae, Hadrosauridae, Ankylosauridae, and possible
Ceratopsidae. The only previously described specimen from this assemblage is a tibia attributed to cf. Ceratopsia by
Riabinin (1939) from the Kara-Cheku locality. This bone is considered currently as Dinosauria indet. We describe
here the most important find from this fauna to date, a partial tyrannosaurid dentary collected by a team from theInstitute of Zoology of the Kazakh Academy of Sciences at the Kara-Cheku locality in 1950. This specimen can be
confidently identified as a derived tyrannosaurine based on the incrassate teeth and the small first alveolus. This is
the first record of a tyrannosaurine from the Late Cretaceous of Kazakhstan and Middle Asia. The age of Zhetysu
dinosaur fauna is possibly Campanian or Maastrichtian.
Key words: Dinosauria, Kazakhstan, Late Cretaceous, Tyrannosauridae, ZhetysuЗАБЫТЫЕ ДИНОЗАВРЫ СЕМИРЕЧЬЯ
(ВОСТОЧНЫЙ КАЗАХСТАН; ПОЗДНИЙ МЕЛ)A.O. Аверьянов1*, Г.-Д. Зюс2 и П.А. Тлеубердина31Зоологический институт Российской академии наук, Университетская наб. 1, 199034 Санкт-Петербург, Россия;Кафедра палеонтологии, Геологический факультет, Санкт-Петербургский государственный университет,16 линия ВО 29, 199178 Санкт-Петербург, Россия; e-mail: dzharakuduk@mail.ru
2
Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, MRC 121, P.O. Box 37012,
Washington, DC 20013-7012, U.S.A.; e-mail: suesh@si.edu
3Институт зоологии, пр. Аль-Фараби 93, Академгородок, 050060 Алматы, Казахстан; e-mail: p.tleuberdina@mail.ruРЕЗЮМЕ
Местонахождения позднемеловых динозавров, открытые в 1925–1927 гг. в бассейне р. Или в предгорьях
Джунгарского Алатау, в центре исторической области Семиречье (Жетысу), являются одними из первых
известных динозавровых местонахождений в Азии. Предварительные определения динозавров из местона-*Corresponding author / Автор-корреспондент

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A.O. Averianov
хождений Семиречья, ревизованные Несовым (1995), включают Sauropoda, Tyrannosauridae, Hadrosauridae,
Ankylosauridae и, возможно, Ceratopsidae. Единственный экземпляр динозавра, описанный ранее из этойфауны, это большая берцовая кость, отнесенная к cf. Ceratopsia Рябининым (1939). Данная находка не может быть определена точнее чем Dinosauria indet. В данной работе мы описываем наиболее важную находку
известную в настоящее время из этой фауны – зубную кость тираннозаврида, найденную в 1950 г. сотрудниками Института Зоологии Казахстана в местонахождении Кара-Чеку. Этот экземпляр может быть надежно определен как Tyrannosaurinae indet. по наличию утолщенных зубов и мелким размерам первой зубной
альвеолы. Это первая находка продвинутого тираннозаврина в позднем мелу Казахстана и Средней Азии.
Возраст динозавровой фауны Семиречья, скорее всего, кампан или маастрихт.
Ключевые слова: динозавры, Казахстан, поздний мел, Tyrannosauridae, Семиречье

INTRODUCTION
In Kazakhstan four principal areas have yielded
fossil remains of the Late Cretaceous dinosaurs (Fig.
1A): 1) the northeastern Aral Sea region; 2) southern
Kazakhstan; 3) the valley of the Ili River; and 4) the
Lake Zayssan depression in eastern Kazakhstan. In
the last area only fragments of dinosaurian egg-shellhave been known from the Manrak Formation on the
Taizhuzgen River since 1959 (Nesov 1995a and references therein). Three other areas have occurrencesof dinosaurian remains. The most productive is the
Bostobe Formation in the northeastern Aral Sea region, which has yielded the stem lambeosaurine Aralosaurus tuberiferus Rozhdestvensky, 1968 and various theropods (Rozhdestvensky 1968; Nesov 1995a;
Dyke and Malakhov 2004; Averianov 2007 andreferences therein). The first dinosaurian bones werediscovered there in 1956 (Rozhdestvensky 1964).
The Syuk Syuk Formation in southern Kazakhstan
has yielded remains of the lambeosaurine Jaxartosaurus aralensis Riabinin, 1939 as well as indeterminate
sauropods, ankylosaurs, and theropods (Riabinin
1939; Rozhdestvensky 1968; Nesov 1995a). Dinosaurian bones were first discovered in this unit in 1923
(Riabinin 1939).
The valley of the Ili River is a part of the historicalregion Zhetysu (Kazakh) or Semirechie (Семиречье,in Russian), which translates into English as “sevenrivers.” This territory was the eastern part of the Russian Turkestan and now corresponds to the southeastern part of Kazakhstan and most of Kyrgyzstan.
Zhetysu encompasses the basins of seven rivers, ofwhich the Naryn, Chu, and Ili rivers are the largest,and two large lakes (Balkhash and Issyk Kul).
The three dinosaur-bearing localities in the valley of the Ili River were discovered in 1925, 1926, and1927, shortly after the first discovery of dinosaurs insouthern Kazakhstan (Kirikov 1927a, b; Yakovlev
1929). In 1928 a Swedish expedition led by the legendary explorer Sven Hedin found several completesauropod skeletons in Jurassic strata of the neighboring Chinese part of Dzungaria (now the northern
region of the Xinjiang Uyghur Autonomous Regionof China). Young (1937) later assigned these finds
to a new taxon, Tienshanosaurus chitaiensis Young,
1937. Between 1922 and 1925 the famous Central
Asiatic Expeditions of the American Museum of
Natural History explored the Gobi Desert of Mongolia and discovered complete dinosaurian skeletonsand the first undisputed dinosaurian eggs and nests(Andrews 1932). Inspired by these discoveries, theAcademy of Sciences of the USSR sent two expeditions to Zhetysu (in 1927 and 1929) to search for
additional dinosaurian fossils (Gartman-Veinberg
1927; Efremov 1931). The results of these expeditions were for the most part disappointing as nocomplete or even partially articulated dinosaurian
skeletons were recovered. Since that time the Cretaceous vertebrate sites in eastern Kazakhstan havenot been considered promising for further exploration and have rarely been visited by paleontologists(Efremov 1931, 1933, 1944; Yur’ev 1954; Rozhdestvensky 1964; Rozhdestvensky and Khozatsky 1967).
This report summarizes the known data about theLate Cretaceous dinosaur-bearing localities in theIli River valley and their potential for future investigation.
Institutional abbreviations. CCMGE, Chernyshev’s Central Museum of Geological Exploration,
Saint Petersburg, Russia; IZK, Institute of Zoology,
Almaty, Kazakhstan; ZIN PH, Zoological Institute of
the Russian Academy of Sciences, Paleoherpetological Collection, Saint Petersburg, Russia.

Jetysu dinosaurs

LATE CRETACEOUS VERTEBRATE
LOCALITIES IN THE ILI RIVER VALLEY
1. Karaoi (= Karoi), Almaty Province, Kazakhstan (Fig. 1B). The local area Karaoi (meaning“black lowland”; “local area” is used here as thetranslation of the Russian geographic term “урочище”) is situated on the left bank of the Ili Riverbetween the Kurtu River (to the north and west),
the Ili River (to the east), and the sands of the MoinKum (to the south) (Fig. 1B). In 1927 D.I. Yakovlev
discovered fragments of large dinosaurian bones ina dry creek near the well Sary-Kuduk in a layer ofbrown conglomerate (Yakovlev 1929). According
to Efremov (1944), the bones are light grey in color,fragmentary, and water-worn. Efremov (1944) listed
remains of Hadrosauridae, Ornithomimidae andTrionychidae for this locality. Additional dinosaurian bones were recovered in this area, specificallyin Tassai Creek, during the 1950s (Bazhanov andKostenko 1958).
2. Shokpakty-Ozek, a dry creek on the left tributary of the Kerbulak River, which is a right tributaryof the Ili River in Almaty Province, Kazakhstan (Fig.
1B). Dinosaurian bones and silicified tree trunks
were discovered in sandy deposits (Bazhanov andKostenko 1958).
3. Zholaman, village and railway station on theTurkestan-Siberia Railway between Saryozek andAlmaty, in the Arkarly Mountains in Almaty Province, Kazakhstan (Fig. 1B). Dinosaurian bones andsilicified tree trunks were found in the vicinity of
the railway station (Bazhanov and Kostenko 1958;
Nurumov 1964).
4. Kara-Cheku (= Karachoku, Karacheko, Karashoky, Dzhurtan, Dzhurtas, Dzhurmas), 2 km southwest of the Kara-Chok village, on the right bank of
the Ili River, Almaty Province, Kazakhstan (Fig. 1B;
Efremov 1944 erroneously indicated a position on
the left bank of the Ili River). The first dinosaurianbones were discovered at this locality by A.P. Kirikov
during prospecting for manganese in 1926 (Kirikov
1927a, b). Kirikov found abundant dinosaurianbones in the Dzhurtan dry creek 2 km southwest of
the Kara-Chok village. Based on identifications by
A.N. Riabinin (cited by Kirikov 1927b) these materials included remains of Hadrosauridae and Ceratopsidae, the last family likely represented by Triceratops
Marsh, 1889. In 1927 the locality was further exploredby the Ili Expedition of the Academy of Sciences

141(Efremov 1931), and limited excavation was undertaken by E.I. Belyaeva and M.G. Prokhorov fromthe Paleontological Institute in Moscow. Large dinosaurian bones and pieces of tree trunks were foundin cross-bedded black conglomerates. According to
Riabinin (1939) the dinosaurian material from KaraCheku consists of poorly preserved bone fragments ofHadrosauridae and Stegosauria. Riabinin (1939, pl.
14, fig. 2) figured a left tibia (cataloged as CCMGE
74/5009) from Kara-Cheku and referred it to cf.
Ceratopsia. This specimen can no longer be located in
the CCMGE collection and thus its affinities cannot
be assessed. However, the proportions of this boneand lack of partial co-ossification with the astragalus
differ from those in Ceratopsidae (e.g., Hatcher etal. 1907: pl. 16). Efremov (1944) cited for the KaraCheku locality the occurrence of Hadrosauridae,
Tyrannosauridae, Ornithomimidae, numerous bonesof Sauropoda (Titanosauridae), possible Stegosauria
and “Acanthopholidae” [=Nodosauridae], as well as
numerous shell fragments referable to Trionychidae.
The reports of stegosaurs and nodosaurs are probably
based on remains of Ankylosauridae (Nesov 1995).
A.K. Rozhdestvensky (1964) mentioned the occurrence of dinosaurian skull and jaw fragments at thislocality but did not consider the site promising for
further work.
In 1950s the locality was revisited by paleontologists from the Laboratory of Paleobiology of the Institute of Zoology of the Kazakh Academy of Sciences(Bazhanov and Kostenko 1958). One dinosaurianbone fragment from this locality was subsequently
analyzed to determine its chemical composition (Bazhanov 1947). Later Bazhanov and Kostenko (1958:
p. 13) reported the discovery at Kara-Cheku of a partial mandible of “Tiranosaurus [sic] sp., similar to T.
baator [sic] from the Late Cretaceous of Mongolia.”
It was stated that V.S. Bazhanov collected this specimen in 1951, but this date was corrected to 1950 bya hand-written note (possibly made by the author)
in the personal copy of the book belonging to one ofus (AA). The specimen was also mentioned in theeditorial footnote to the paper by Khozatsky (1957:
p. 20) devoted to the history of trionychid turtles in
Kazakhstan as a lower jaw of “Tiranosaurus [sic] aff.
bater [sic] from Karacheko.”
The jaw fragment (Fig. 2A-C) is now on display
at the Museum of Nature in Almaty where it is accompanied by the label “Tirannosaurus [sic] sp., acarnivorous tyrannosaur; jaw fragment; Sary-Ozek,

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A.O. Averianov

Fig. 1. Map of Kazakhstan (A) showing position of the principal areas with dinosaur localities (1, northeastern Aral Sea region; 2, southern
Kazakhstan; 3, valley of the Ili River; 4, Lake Zayssan depression) and map of the valley of the Ili River (B) in the southwestern foothillsof Dzhungar Alatau in eastern Kazakhstan with position of dinosaur-bearing localities (1, Karaoi; 2, Shokpakty-Ozek; 3, Zholaman; 4,
Kara-Cheku; 5, Kshi-Kalkan). Map B is modified from http://maps.google.ru/maps.

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Jetysu dinosaurs

local area Karaoi; collected by V.V. Kuznetsov; identified by T.N. Nurumov” (Fig. 2D).
L.I. Khozatsky (1957: p. 19) noted shell fragmentsof unusually large trionychid turtles in the collection
made during the excavation in “Dzhurmas” [=Dzhurtan] Creek in 1927. He erroneously thought thatDzhurtan Creek is part of the Kshi-Kalkan locality(see below). The editorial footnote to this paragraphindicated that “this locality is practically exhausted.”
However, it is not clear if this comment referred to
the Kshi-Kalkan or the Dzhurtan site.
L.A. Nesov (1995b) described a carapace fragment of Adocus sp. collected by E.I. Belyaeva andM.G. Prokhorov from the Dzhurtas ravine in 1927.
He followed Khozatsky in the erroneous referral of
Dzhurtas to the Kshi-Kalkan locality (see also Nesov
1995a, 1997). Syromyatnikova and Danilov (2009)
assigned this specimen and a few other shell fragments from the 1927 excavation (collection ZIN PH92) to a new species, Adocus dzhurtasensis Syromyatnikova et Danilov, 2009.
5. Kshi-Kalkan (=Kalkan, Malyi Kalkan), southwest margin of the Kshi-Kalkan Mountains, on theright bank of the Ili River, Almaty Province, Kazakhstan (Fig. 1B). Dinosaurian bones were first discovered here in 1925 by a geological expedition led
by V.G. Mukhin (Kirikov 1927a). Kirikov (1927b)
cited for the Kshi-Kalkan locality the occurrence ofHadrosauridae and Ceratopsidae (tibia and fibula
fragment of Triceratops) based on identifications by
A.N. Riabinin. The Ili Expedition of the Academy of
Sciences of the USSR further explored this locality
in 1927 (Efremov 1931). Dinosaurian bones and tree
trunks occur in a coarse conglomerate cemented bywhite sandstone. According to Efremov (1944) themost common bones were those of Hadrosauridae.
There were also numerous remains of theropods(Tyrannosauridae and Ornithomimidae). Additional
faunal elements included Ceratopsidae, Stegosauridae and Acanthopholidae [=Nodosauridae]. Efremov (1944: p. 45) noted that “at this locality forthe first time among other localities were foundundoubted ceratopsids like Triceratops. There arelarge dorsal plates, different from those known forankylosaurs and extremely similar to plates typicalfor stegosaurs.” A discovery of stegosaurian remains
is rather unlikely for the Late Cretaceous. Possibly
this description made reference to ankylosaurian
osteoderms. Efremov also noted bones of sauropods
possibly referable to Titanosauridae. Among turtles,

the most common remains are plates of Trionychidae.
There are also some shell elements of “Testudinidae”[=Adocidae?]. In 1932 a party from the Geological
Exploration Bureau of Gas Fields collected additional dinosaurian remains from the Kshi-Kalkan
Mountains, in a gully called Enbekish. These remains
include two large fragments of indeterminate bones
and a dinosaurian rib fragment (CCMGE 1/4242).
Rozhdestvensky (1964) considered Kshi-Kalkan notparticularly promising for further exploration.
SYSTEMATICS
Dinosauria Owen, 1842
Saurischia Seeley, 1887
Theropoda Marsh, 1881
Tyrannosauroidea Osborn, 1905
Tyrannosauridae Osborn, 1905
Tyrannosaurinae Osborn, 1905
Tyrannosaurinae gen. et sp. indet.
(Fig. 2)
Material. IZK 33/MP-61, a right dentary missing
the posterior portion and all functional teeth.
Locality and horizon. Kara-Cheku, Almaty Province, Kazakhstan. Unnamed Late Cretaceous unit.
Description. The dentary lacks a few missing
smaller pieces along the alveolar margin and much of
the posterior part of the bone with the greater part of
the Meckelian fossa and the posteroventral process ofthe dentary. On the lingual surface of the dentary, apiece is missing between the fourth and sixth alveoli
and a smaller fragment at the ninth alveolus (Fig.
2A–C); both were restored in colored plaster. The
preserved length of the dentary is about 49 cm. The
bone attains its greatest height between the third andfourth alveoli (about 14 cm). The lowest point of thedentary is at the level of the eighth alveolus. Thus thedorsal margin of the element is slightly convex anteriorly and concave posteriorly. The ventral marginof the dentary is nearly straight. The anterior marginof the element extends obliquely so that the dorsal
margin projects anteriorly beyond the ventral margin
by three alveoli. The dentary is widest labiolinguallyat the level of the fourth alveolus and gradually becomes narrower both anteriorly and posteriorly.
The labial surface of the dentary bears two rows ofpoorly preserved neurovascular foramina. The ventral

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A.O. Averianov

Fig. 2. Tyrannosaurinae indet., IZK 33/MP-61, partial right dentary in dorsal (A), lingual (B), and labial (D) views with accompanying
outline drawings showing position of parts restored in plaster (grey) and the museum exhibit label (D). Abbreviations: ipl, interdental
plates; Mf, Meckelian fossa; Mgr, Meckelian groove; sgr, supradental groove; sy, symphysis. Numbers 1-10 denote tooth positions. Scalebar = 10 cm.

row of openings extends close to the ventral marginof the bone, whereas the dorsal row is separated fromthe dorsal margin by a distance equal to one fourth or
one third of the height of the dentary. Another row
of large foramina extends along the anterior marginof the dentary.
On the lingual side of the dentary the symphyseal
surface is rather smooth and extends posteriorly toward the level of the fourth alveolus. However, theposterior extent of the surface cannot be determined
due to damage to the bone in this region. The Meckelian groove can be clearly traced only between theeighth and eleventh alveoli. It is narrow in its preserved anterior portion; posteriorly, its ventral edge
is not clearly visible. Most of the posterior end of thedentary is missing. The only intact part is situatedjust below the Meckelian groove and contains a small
triangular depression, which represents the anterior
end of the Meckelian fossa. This end is situated at
the level of the (missing) twelfth alveolus, as in othertyrannosaurines (e.g., Maleev 1974: fig. 14; Brochu
2003: fig. 40B, D; Hone et al. 2011: fig. 3B, D).

The interdental plates are well developed andfused with the lingual ends of the interalveolar septa.
The interdental plates separated from each other, as inother tyrannosaurids (Currie 2003). They are also set
off from the lingual surface of the mandibular ramus
by a distinct groove that probably housed the dental
lamina. The better preserved posterior interdental
plates are triangular and lack distinct sculpturing.
The incomplete dentary preserves eleven alveoli. The
original number of tooth positions in the dentary may
have been as high as fifteen based on the relative position of the anterior end of the Meckelian fossa (seeabove). The first alveolus of the dentary is only about
half as large as the second. It is incomplete anteriorly
but there appears to be no space between the tooth
row and mandibular symphysis. The fourth alveolus
is the largest, although its size appears somewhat
exaggerated by the loss of the lingual wall. The moreposterior alveoli gradually decrease in size posteriorly. Most alveoli are empty. Remnants of roots arepreserved in the third and eighth alveoli. The tenthalveolus contains the broken crown of a replacement

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Jetysu dinosaurs

tooth with a distinct mesial carina. The distal part ofthis tooth has been destroyed. The mesiodistal lengthof the replacement tooth crown is about 25 mm andits labiolingual width is 17.5 mm (width-to-length
ratio of 70%).
PHYLOGENETIC POSITION
OF THE KARA-CHEKU TYRANNOSAURINEIZK 33/MP-61 can be confidently referred to
Tyrannosauroidea based on the following combination of character states: large size; strongly concave
dorsal margin of dentary in labial (lateral) view; dorsoventrally shallow Meckelian groove; and unfusedinterdental plates (Currie 2003; Currie et al. 2003;
Brusatte et al. 2010; Carr and Williamson 2010;
Hone et al. 2011). An almost straight anterior marginof dentary is also characteristic for Tyrannosauroidea(Carr and Williamson 2010; Brusatte et al. 2010),
although the transition between the anterior andventral margins of IZK 33/MP-61 is below the third
rather than the fourth alveolus (as in other tyrannosauroids). The labiolingually thick (incrassate) teethof IZK 33/MP-61, based on the partial replacement
tooth in the tenth alveolus, supports assignment of
this specimen to Tyrannosauridae. Non-tyrannosaurid tyrannosauroids as well as some tyrannosaurids(Alioramus Kurzanov, 1976, Teratophoneus Carr,
Williamson, Britt et Stadtman, 2011) have labiolingually flattened tooth crowns with a labiolingual(transverse) width at the base of less than 60% of themesiodistal length (Brusatte et al. 2010, 2012). In
Albertosaurus Osborn, 1905, Daspletosaurus Russell,
1970, and Gorgosaurus Lambe, 1914, the transverse
width of the crown base is greater than 60% of themesiodistal length, whereas in Tarbosaurus Maleev,
1955 and Tyrannosaurus Osborn, 1905 the transverse
width of the crown is nearly equal to its mesiodistal
length. The ontogenetic and positional variability ofthis character state has not yet been examined in detail. In IZK 33/MP-61 the single preserved posterior
tooth crown has width to length ratio 70%, which isalmost identical to the ratio for a dentary tooth ofTarbosaurus figured by Maleev (1974: fig. 15). IZK33/MP-61 is clearly different from Alioramus fromthe Late Cretaceous of Mongolia in having labiolingually thick (incrassate) teeth and a relatively deeper, more robust dentary (Brusatte et al. 2009, 2012).
IZK 33/MP-61 differs from other tyrannosaurines inthe smooth texture of the dentary symphysis, which

is distinctly rugose in Tyrannosaurus and Tarbosaurus(Brusatte et al. 2010). However, it shares with these
two taxa the presence of a distinctly smaller firstdentary alveolus, a feature absent in other tyrannosauroids (Brusatte et al. 2010). This character state isalso present in the tyrannosaurine Zhuchengtyrannus
Hone et al., 2011 from the Campanian of Shandong
Province, China (Hone et al. 2011). The incrassate
teeth and reduced first dentary alveolus of IZK 33/
MP-61 support its referral to derived Tyrannosaurinae including Tarbosaurus, Tyrannosaurus, andZhuchengtyrannus. Thus the original identificationof this specimen as Tyrannosaurus or Tarbosaurus was
not far off the mark.
DISCUSSION
The Late Cretaceous dinosaurian fauna of Zhetysu (eastern Kazakhstan) has been known sincethe 1920s, almost as long as the famous dinosaurian
assemblages from the Gobi Desert of Mongolia. Efremov (1944) noted that more than 1500 catalogued
specimens had been collected from the Kazakh
localities. To date, however, only a single fossil, an
incomplete tibia (CCMGE 74/5009) from KaraCheku, has been reported in the literature (Riabinin
1939: pl. 14, fig. 2). The Zhetysu fauna, based on thereview by Nesov (1995a), includes five dinosauriangroups: Sauropoda, Tyrannosauridae, Hadrosauridae, Ankylosauridae, and possible Ceratopsidae. The
presence of the last group (which is rare in Asia)
cannot be confirmed. The tibia figured by Riabinin
is not referable to Ceratopsidae. The first four groupsof dinosaurs are also known from the Maastrichtianage Nemegt Formation of the Gobi Desert, including
the tyrannosaurine Tarbosaurus (Weishampel et al.
2004). Hadrosauridae, Ankylosauridae, the tyrannosaurine Zhuchengtyrannus, Ceratopsidae and Leptoceratopsidae have been recorded from the Campanian
Wangshi Series of Shandong Province, China (Xu etal. 2010a, b; Hone et al. 2011). Thus, the tyrannosaurine from Kara-Cheku and its associated fauna may
well be Campanian or Maastrichtian in age. Nesov(1995b) and Syromyatnikova and Danilov (2009)previously considered the Zhetysu assemblage Santonian to early Campanian in age. Additional work isneeded to constrain the age of this assemblage.
IZK 33/MP-61 represents the first record of a
derived tyrannosaurine with incrassate teeth fromthe territory of Kazakhstan and from Middle Asia.

146

The Zhetysu region clearly has significant potential
for future dinosaurian discoveries.
ACKNOWLEDGMENTS
We are grateful to Dmitry Grigoriev for taking photographs of IZK 33/MP-61 and to Philipp Trikolidi for thehelp with geological literature. We thank Stephen Brusatte(American Museum of Natural History, New York) for
reviewing the manuscript and offering helpful suggestions.
The laboratory work of AA was supported by the St. Petersburg State University (grant NIR 3.39.148.2011) and
Ministry of Education and Science of Russian Federation(contract 16.518.11.7070).

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