Translator Disclaimer
7 February 2012 First Evidence of a Mamenchisaurid Dinosaur from the Upper Jurassic-Lower Cretaceous Phu Kradung Formation of Thailand
Author Affiliations +
Abstract

An isolated posterior cervical vertebra of a sauropod discovered at Phu Dan Ma (Kalasin Province, northeastern Thailand) is the first informative postcranial specimen from the Phu Kradung Formation, a Upper Jurassic to Lower Cretaceous continental unit. The vertebra is referred to the family Mamenchisauridae, otherwise mainly known from China. In addition, spatulate teeth from the same formation and a mid-dorsal vertebra from the Upper Jurassic Khlong Min Formation of southern Thailand are reassigned to this family. The occurrence of mamenchisaurids in the earliest Cretaceous of Thailand supports a hypothesis of geographical isolation of Central, Eastern, and Southeast Asia during the Late Jurassic. It also suggests that the main changes in their dinosaur assemblages occurred during the Early Cretaceous, rather than at the Jurassic-Cretaceous boundary.

Introduction

The vertebrate assemblages of Thailand in the Late JurassicEarly Cretaceous were diverse and widespread through the northeastern and northern regions, and only a few elements have been found in the southern peninsula (Buffetaut and Suteethorn 1998b; Buffetaut et al. 2003; Cavin et al. 2007; Cuny et al. 2007). Fossils are known from the Phu Kradung Formation on the Khorat Plateau of the Indochina Block (Buffetaut and Ingavat 1980; Buffetaut and Suteethorn 1998a, 2007; Buffetaut et al. 2001; Tong et al. 2006) and the Khlong Min Formation on the Shan-Thai Block (Buffetaut et al. 1994, 2005; Tong et al. 2002). Although the age of the Phu Kradung Formation is controversial, its vertebrate fauna is similar to those from the Late Jurassic of China (Buffetaut et al. 2006). Previously known informative sauropod material consists of isolated teeth from the Phu Kradung Formation (Buffetaut and Suteethorn 1998a) and a vertebra from the Khlong Min Formation (Buffetaut et al. 2005). They were interpreted as euhelopodids, but the validity of this family has recently been challenged (Wilson and Sereno 1998; Wilson 2002; Canudo et al. 2002; Wilson and Upchurch 2009).

In 2004, Pha Kru Partyatti Thummarakkit, the head of the monks at the temple Sum Nak Song Rakkit Thumma Wiwek, discovered some dinosaur bones on the hill of Phu Dan Ma (locality KS26) in Kuchi Narai District (Kalasin Province; northeastern Thailand) and reported this discovery to the Department of Mineral Resources (DMR) in Bangkok. In August 2004, a DMR team examined several dinosaur bones and bone fragments that had been collected by the monks. These bones included theropod teeth, fragments of sauropod limb bones, teeth and osteoderms of crocodiles, and turtle shells. A complete vertebra of a sauropod dinosaur was kept in situ. It was excavated and is now housed in the Sirindhorn Museum collections in Sahat Sakhan District, Kalasin Province. We report here the discovery of a well-preserved sauropod vertebra from the Phu Kradung Formation and provide some biogeographical hypotheses.

Institutional abbreviations.—C, National History Museum of Chongqing, Chongqing, China; CCG V, “Chengdu College of Geology” now “Chengdu University of Technology”, Sichuan Province, Chengdu, China; DMR, Department of Mineral Resources, Bangkok, Thailand; PUM.R, Paleontological Museum of Uppsala University, Uppsala, Sweden; SM MD, Sirindhorn Museum, Kalasin Province, Kalasin, Thaialnd; SDRC KB, Sahatsakhan Dinosaur Research Centre, Kalasin Province, Kalasin, Thailand; SM KS, Sirindhorn Museum, Kalasin Province, Kalasin, Thailand; T, Zigong Dinosaur Museum, Sichuan Province, Zigong, China; ZDM, Zigong Dinosaur Museum, Sichuan Province, Zigong, China.

Other abbreviations.—EI, Elongation Index.

Geological setting

The Phu Dan Ma locality is in the uppermost part of the Phu Kradung Formation near a conformable contact with the overlying Phra Wihan Formation (Fig. 1). Racey et al. (1996) noted that the contact between the Phu Kradung and Phra Wihan formations is fairly gradational and that it is not easy to define this limit in the field. It is thus not unlikely that the bone beds of the Phu Kradung Formation can be considered as belonging to the basalmost part of the Phra Wihan Formation. The Phu Kradung Formation is a unit of the non-marine Mesozoic Khorat Group. Its thickness varies from 800 to 1200 m. This unit is composed of brown siltstone, claystone, sandstone, and conglomerate beds. In its upper part claystone and calcrete nodules, caliches and nodular silcretes are found (Meesook et al. 2002). The uppermost part contains cycles of fining-upward sequences: cross-bedded sandstone, fine-laminated sandstone, and massive mudstone (Horiuchi et al. 2008); the cycles suggest deposition in a meandering river system. Meesook (2000) noted that the vertebrate remains are usually found in channel conglomerate intercalated in massive mudstone units, considered as floodplain deposits (Racey et al. 1996; Meesook 2000). The specimen from Phu Dan Ma was found in greenish to grey conglomeratic sandstone with calcretes (indicating a subhumid to arid climate) overlying the sequence of mudstone and claystone interbedded with siltstones where dinosaur teeth and turtle shells were found.

Fig. 1.

A. Location of the study area on the map of Thailand. B. A map of sauropod distribution in the Late Jurassic-Early Cretaceous, Phu Kradung Formation of the Kalasin-Mukdahan region, northeastern Thailand; Phu Dan Ma in Kuchi Narai District, Kalasin Province and Dan Luang in Khamcha-i District, Mukdahan Province.

f01_459.jpg

The age of the Phu Kradung Formation is controversial. It has yielded abundant vertebrates, including the crocodilian Sunosuchus thailandicus Buffetaut and Ingavat, 1980, temnospondyl amphibians (Buffetaut et al. 1994), cryptodiran turtles (Tong et al. 2006), including the large trionychoid Basilochelys macrobios (Tong et al. 2009), and the tibia of a sinrap torid theropod (Buffetaut and Suteethorn 2007); the fauna is generally similar to those from the Late Jurassic of Sichuan and Xinjiang, China (Buffetaut and Suteethorn 1998b; Buffetaut et al. 2003, 2006). Le Loeuff et al. (2002) noted that many of the vertebrate sites are located at the top of the thick Phu Kradung Formation and that its vertebrate assemblages show resemblance to the ichnological faunas of the overlying Lower Cretaceous (?Neocomian) Phra Wihan Formation. These authors suggested that the uppermost part of the Phu Kradung Formation might be basal Cretaceous rather than Late Jurassic in age, a hypothesis supported by Racey and Goodall (2009) on the basis of palynological evidence (see Buffetaut and Suteethorn 2007 for discussion). New studies of the stratigraphy of dinosaur beds in the Khorat Group are needed to clearly understand the Phu Kradung-Phra Wihan contact and correlate the vertebrate assemblage and palynological evidence. In the present stage of knowledge a latest Jurassic or earliest Cretaceous age is likely for the Phu Kradung Formation.

Fig. 2.

Distribution of main groups of vertebrates in the non-marine formations of Thailand (courtesy of Lionel Cavin, Muséum d'Histoire Naturelle, Geneva). Fm., Formation.

f02_459.jpg

Systematic palaeontology

Dinosauria Owen, 1942
Sauropoda Marsh, 1878
Mamenchisauridae Young and Zhao, 1972

  • Diagnosis.—Posterior cervical vertebrae of mamenchisaurids can be diagnosed by their bifid neural spine with a U-shaped cleft and no median tubercle; the centrum and neural spine are entirely filled with numerous small pneumatic camellae (cancellous inner structure); the centra show large pleurocoels with successive generations of smaller chambers.

  • Remarks.—The family Mamenchisauridae was erected by Young and Zhao (1972) to include the genus Mamenchisaurus. It was generally considered as a junior synonym of the family Euhelopodidae Romer, 1956 (= Helopodidae Wiman, 1929), which included most of the Middle Jurassic to Early Cretaceous Chinese sauropod taxa, such as Euhelopus, Omeisaurus, and Mamenchisaurus (He et al. 1988; Upchurch 1995, 1998; Buffetaut et al. 2005). A recent phylogenetic analysis by Wilson and Upchurch (2009) concludes that Euhelopus belongs to the Titanosauriformes (see also Wilson and Sereno 1998 and Wilson 2002). According to this interpretation, the family Euhelopodidae may include Asian and European Early Cretaceous sauropods (Canudo et al. 2002; Wilson and Upchurch 2009) but does not include Mamenchisaurus and Omeisaurus.

    After denying the validity of a monophyletic Asian sauropod clade uniting Euhelopus, Mamenchisaurus, and Omeisaurus in the family Euhelopodidae (cf. Dong et al. 1983; He et al. 1988; Upchurch 1995, 1998; Martin-Rolland 1999; Buffetaut et al. 2002, 2005; Upchurch et al. 2004a), Wilson (2002) erected the family Omeisauridae to name a node including Omeisaurus and Mamenchisaurus. We consider Omeisauridae (Wilson 2002) as a junior synonym of Mamenchisauridae Young and Zhao, 1972. Lü et al. (2008) later assigned Eomamenchisaurus yuanmouensis from the Middle Jurassic of Yunnan Province, China to the Mamenchisauridae, although its synapomorphic characters are ambiguous. Eomamenchisaurus shares some characters with Omeisaurus, such as: slightly opisthocoelous to amphicoelous dorsal centra; pubic peduncle situated at middle part of ilium; length ratio of tibia to femur about two-thirds. The family Mamenchisauridae (= Omeisauridae Wilson 2002) is a member of Eusauropoda, and comprises Asian sauropod taxa from the Middle Jurassic to the earliest Cretaceous such as Omeisaurus, Eomamenchisaurus, Mamenchisaurus, and Thai specimens (He et al. 1988; Ouyang and Ye 2002; Lü et al. 2008). The group of Somphospondyli comprising Euhelopus zdanskyi Wiman, 1929; Erketu ellisoni Ksepka and Norell, 2006; Dongbeititan dongi Wang, You, Meng, Gao, Cheng, and Liu, 2007; cf. Euhelopus sp. Barrett and Wang, 2007; Daxiatitan binglingi You, Li, Zhou, and Ji, 2008 from the Early Cretaceous of China and Mongolia, and probably some unnamed taxa from Spain and Russia (Canudo et al. 2002; Averianov et al. 2003) might be a monophyletic group (= Euhelopodidae sensu Canudo et al. 2002). However, Wilson and Upchurch (2009) suggested that detailed phylogenetic analyses supporting the group are needed to resurrect the term Euhelopodidae.

  • Fig. 3.

    Posterior cervical vertebra of Mamenchisaurus sp. from Phu Dan Ma, Kalasin Province, Thailand, Phu Kradung Formation, Late Jurassic-Early Cretaceous. Vertebra (SM KS26–4), right rib (SM KS26–2), and left rib (SM KS26–3) in anterior (A; A2, close-up view of neural spine showing attachment scar for interspinal elastic ligament), left lateral (B), posterior (C), right lateral (D; D2, close-up view of articular condyle showing a cancellous internal structure), and dorsal (E) views.

    f03_459.jpg

    Genus Mamenchisaurus Young, 1954

  • Type species: Mamenchisaurus constructus from the Upper Jurassic Shangshximiao Formation, Yibin, Sichuan Province, China.

  • Mamenchisaurus sp.
    Figs. 35.

  • Material.—SM KS26–4, nearly complete posterior cervical vertebra; SM KS26–2, SM KS26–3, fragmentary ribs from Phu Dan Ma, Phu Kradung Formation (Upper Jurassic?Lower Cretaceous), northeastern Thailand.

  • Description.—The vertebra SM KS26–4 is nearly complete and well preserved, except the right parapophysis, diapophysis, and postzygapophysis, and the posterior portion of the centrum which are damaged (Figs. 3, 4). The vertebra is distorted and slightly compressed anteroposteriorly and laterally and the postzygapophysis is bent forward. The ribs were found articulated to the vertebra. The capitulum and tuberculum processes of the right rib (SM KS26–2) are missing. The parapophyses are located on the centrum ventrolaterally and the rib shaft is bent outward oblique to the long axis of the centrum. This feature indicates an intermediate position between cervical and dorsal vertebrae. In addition, the position of the parapophyses is as low as the ventral surface of the centrum and the shape of the rib is reminiscent of cervical ribs. Thus, SM KS26–4 is identified as one of the most posterior cervical vertebrae.

    The vertebra is relatively high and short anteroposteriorly (Table 1). The centrum is strongly opisthocoelous with an Elongation Index (EI) about of 1.4 (EI = anteroposterior length/height of posterior face; sensu Upchurch 1998; Wilson 2002). The ventral surface of the centrum is concave and has a stout median keel. The centrum and neural arch are pneumatised (Wedel 2009). The breaks of the anterior articular surface show pneumatic camellate structures, circular cells separated by thin bone laminae (Wedel et al. 2000). Laterally, the pneumatic fossa occupies most of the lateral surface of the centrum. A horizontal lamina (or “supracentral lamina”; Osborn and Mook 1921) divides the pneumatic fossa into upper and lower parts.

    The parapophysis is robust and projects ventrolaterally.

    Its dorsal surface is excavated by a pneumatic fossa. The parapophyseal facet is sub-circular.

    The neural canal is triangular in anterior view and spindle-shaped in posterior view. The neural spine is relatively low. The U-shaped cleft between the bifid spines is shallow and has no median spine. Ventral to the cleft, a prominent scar is marked at the base of the neural spine in anterior view. It probably represents the mineralised attachment area for the elastic ligament (Schwarz et al. 2007).

    The prezygapophyseal facets are large, subrectangular and convex transversely. Triangular pneumatic fossae excavate below the prezygapophysis and postzygapophysis and are limited medially by the intraprezygapophyseal and intrapostzygapophyseal laminae, respectively.

    The diapophysis projects outward from the neural arch and curves ventrally toward its distal end. The diapophysis is flattened anteroposteriorly, with internal pneumatic cavities extending both anteriorly and posteriorly. A large pneumatic fossa excavates the diapophysis ventrally between the anterior and posterior centrodiapophyseal laminae.

    Both ribs (SM KS26–2 and SM KS26–3) are preserved but not complete (Fig. 5). They show a sharp angle (45°) between the capitulum and tuberculum with a median ridge. The tuberculum is transversely wide and has a rectangular facet, while the capitulum is a peduncle-like structure with a circular facet.

  • Discussion.—The EI of the centrum of SM KS26–4 is reminiscent of the long-necked Chinese sauropods: it is close to that of the 17th cervical vertebra of Omeisaurus tienfuensis and that of the 18th cervical vertebra of Mamenchisaurus hochuanensis and is between those of the 17th and 18th cervical vertebrae of Euhelopus zdanskyi (Table 2). The large pleurocoel with successive generations of smaller chambers of SM KS26–4 is similar to that of Camarasaurus (Osborn and Mook 1921: pl. 69) and differs, from Euhelopus, in which the pleurocoel is a simple and shallow concavity. Ouyang and Ye (2002) noted that there is no pleurocoel in the cervical vertebrae of M. youngi, but in fact the lateral surface of the centrum of Mamenchisaurus is excavated by a large concavity (Young and Zhao 1972: pl. 14; Ouyang and Ye 2002: pl. 8). Moreover, the centrum and neural arch of SM KS26–4 are entirely filled with numerous small pneumatic camellae like those of Mamenchisaurus (Russell and Zhang 1993; Ouyang and Ye 2002), Omeisaurus (He et al. 1988), and a vertebra from the Jurassic of Southern Thailand (Buffetaut et al. 2005). This cancellous inner structure differs from the spongy bones of somphospondylans such as Euhelopus and the saltasaurid Ampelosaurus Le Loeuff, 1995, the latter having more irregularly shaped and relatively smaller camellate cells. The camellate structure of SM KS26–4 is different from the solid bone of Phuwiangosaurus, from the overlying Sao Khua Formation (Martin 1994). Wedel et al. (2000) proposed that the pneumatic camellate structure in vertebrae (in both the centrum and neural spine) evolved independently at least twice in the Sauropoda: in Mamenchisaurus and in the Somphospondyli, a group defined as titanosauriforms more closely related to Saltasaurus than to Brachiosaurus (Wilson and Sereno 1998).

    The neural spine of SM KS26–4 is reminiscent of the bifid spine of Mamenchisaurus hochuanensis and M. youngi (Young and Zhao 1972; Ouyang and Ye 2002). The cleft is broader with a U-shape in Opisthocoelicaudia Borsuk-Bialynicka, 1977 and a V-shape in Apatosaurus ajax (Upchurch et al. 2004b), whereas it is deep and steep in Camarasaurus (Osborn and Mook 1921: pl. 69: 13) and Phuwiangosaurus Martin, Buffetaut, and Suteethorn, 1994. The bifid spine of Euhelopus has a median tubercle, which is an autapomorphy of the genus (Wilson 2002). Omeisaurus differs from the others as its spine is undivided (He et al. 1988). The short neural spine in the posterior cervical vertebra with a shallow U-shaped cleft is considered as an autapomorphy of Mamenchisaurus.

  • Fig. 4.

    Schematic drawing of mamenchisaurid posterior cervical vertebra from Phu Dan Ma, Kalasin Province, Thailand, Phu Kradung Formation, Late Jurassic-Early Cretaceous. Vertebra (SM KS26–4), right rib (SM KS26–2), and left rib (SM KS26–3), in anterior (A), left lateral (B), posterior (C), right lateral (D), and dorsal (E) views.

    f04_459.jpg

    Table 1.

    Measurements (in mm) of cervical vertebra (SM KS26–4) from Phu Dan Ma, Phu Kradung Formation, Thailand. Asterisks indicate approximate values.

    t01_459.gif

    Table 2.

    Comparative measurements (in mm) of cervical and dorsal vertebrae from various sauropods. Applied from Wiman (1929), Young and Zhao (1972), He et al. (1988), and Ouyang and Ye (2002).

    t02_459.gif

    Fig. 5.

    Posterior cervical rib of Mamenchisaurus sp. from Phu Dan Ma, Kalasin Province, Thailand, Phu Kradung Formation, Late Jurassic-Early Cretaceous. Left rib (SM KS26–3) in posterior (A) and medial (B) views.

    f05_459.jpg

    Mamenchisauridae indet. A
    Fig. 6A–C.

  • Material.—SM MD3–53, SM MD3–54, SM MD3–62, isolated teeth from Dan Luang, Phu Kradung Formation, northeastern Thailand.

  • Remarks.—Buffetaut and Suteethorn (1998a, 2004) described spatulate teeth from the Dan Luang locality in the Phu Kradung Formation (Fig. 6), and recognized the resemblances between the Thai specimens and Omeisaurus based on the presence of denticles on unworn teeth (Buffetaut and Suteethorn 2004: figs. 1, 3). However, denticles are also present in Mamenchisaurus (Russell and Zheng 1993). Teeth from Thailand are similar to those of Mamenchisaurus fuxiensis (= Zigongosaurus fuxiensis Hou, Chao, and Chen, 1976) from the Wujiaba locality in the lower part of the Upper Shaximiao Formation of Zigong, China (Haiyan Tong and Hui Ouyang, personal communication 2009). Although Ouyang and Ye (2002) regarded the latter as indeterminate, because of the presence of a mosaic of characters found in Omeisaurus and Mamenchisaurus, these teeth belong to the family Mamenchisauridae as shown below.

    The presence of a lingual boss has been recognized in various sauropods such as Mamenchisaurus (Russell and Zheng 1993: pl. 2; Ouyang and Ye 2002: figs. 9–12), Omeisaurus (He et al. 1988: fig. 16), Euhelopus (Wiman 1929: pl. 2), Camarasaurus (Osborn and Mook 1921: pl. 60) and isolated teeth from Thailand (Buffetaut and Suteethorn 2004: fig. 1) and Spain (Canudo et al. 2002: fig. 2). It seems that among these sauropods, those from younger formations, namely Euhelopus and the Spanish specimen (Wiman 1929; Canudo et al. 2002; Barrett and Wang 2007), show a complex pattern of cingular structure. Some of their teeth (Wiman 1929: pl. 2: 12, 15, 17, 18, 23) have a lingual boss associated with a cingulum, a horizontal ridge and some (Wiman 1929: pl. 2: 14, 16,19, 21; Canudo et al. 2002: figs. 2, 3) have two lingual bosses, mesially and distally, associated with a medial ridge or (third) boss forming a pseudo-cingulum. These differences possibly result from their positions in the tooth row such as anterior-posterior or upper-lower teeth. Teeth of sauropods from older formations, namely Mamenchisaurus, Omeisaurus, and Thai specimens (Russell and Zheng 1993: fig. 4; Zhang et al. 1998: pl. 1; Ouyang and Ye 2002: figs. 11, 12; He et al. 1988: pl. 2; Buffetaut and Suteethorn 2004: fig. 1), show a single distal boss with a smoothly curved lingual concavity. We agree with Canudo et al. (2002) that the complexity of the cingular structures (a cingulum and boss) possibly represents a derived state (Fig. 6). Regardless, it should be stated that this feature is not present in all preserved specimens and is sometimes present in more primitive sauropods such as Camarasaurus (Osborn and Mook 1921: pl. 60: 6a). The spatulate teeth from Dan Luang are thus similar to those of Mamenchisaurus and Omeisaurus on the basis of primitive characters: presence of tooth denticles, single boss on lingual surface.

  • Fig. 6.

    Teeth of mamenchisaurids and the titanosauriform Euhelupus zdanskyi. A–C. Mamenchisauridae indet. A teeth (SM MD3-53, -62, -54, respectively) from Dan Luang, Mukdahan Province, northeastern Thailand, Phu Kradung Formation, Late Jurassic-Early Cretaceous, in cast showing a lingual boss (A1–C1), and in lingual (A2–C2), labial (A3–C3), distal (C4), mesial (C5), dorsal (C6), and ventral (C7) views. D–F. Euhelupus zdanskyi Wiman, 1929 teeth (PMU.R-182i, -182g, -182b, respectively) from central Shandong Province, China, Mengyin Formation, Early Cretaceous, in lingual view showing cingulum and boss. G–I. Mamenchisaurus fuxiensis Hou, Zhao and Chu, 1976 teeth (C. 1042) from Wujiaba, Zigong Perfecture, China, Upper Shaximiao Formation, Late Jurassic, in lingual view.

    f06_459.jpg

    Mamenchisauridae indet. B

  • Material.—SDRC KB1-1, a dorsal vertebra from Khlong Thorn District, Krabi, Khlong Min Formation, southern Thailand.

  • Remarks.—A sauropod vertebra from the Upper Jurassic Khlong Min Formation of southern Thailand was described by Buffetaut et al. (2005). The shape of the centrum and the position of the parapophysis indicate a position midway through the dorsal vertebral series and its pneumatic camellate structure resembles that of the mamenchisaurids and Titanosauriformes (Wedel 2003). Buffetaut et al. (2005) noted the difference between these groups using pleurocoel shape, the pleurocoels of Titanosauriformes tending to have a tapering, acute caudal margin. They considered the vertebra from southern Thailand as a mid-dorsal vertebra of a euhelopodid (sensu Upchurch 1995, 1998) on the basis of camellate structure and the shape of the pleurocoel. This vertebra can be excluded from the genus Euhelopus because of the lack of a “K”-lamina, an autapomorphic character of Euhelopus recognized by Wilson and Upchurch (2009). It resembles Mamenchisaurus and Omeisaurus in several respects and accordingly can be placed in the family Mamenchisauridae.

  • Conclusions

    The posterior cervical vertebra (SM KS26–2 to KS26–4) from Phu Dan Ma is assigned to Mamenchisaurus sp. in the family Mamenchisauridae, based on the following characters: short posterior cervical vertebra (EI = 1.4) with camellate internal structure; bifurcated neural spine with shallow U-shaped cleft. Because of the lack of unambiguous characters of the isolated teeth from the Dan Luang locality and the dorsal vertebra from southern Thailand, a generic attribution cannot be confirmed. However, they share several characters with the Mamenchisauridae and we assign these remains to the family Mamenchisauridae.

    Sauropod remains from the Phu Kradung Formation of Thailand thus belong to a family of Jurassic sauropods first described from China, and their occurrence in Thailand can be interpreted as evidence of faunal links between the Indochina Block and mainland Asia during the Late Jurassic-Early Cretaceous. This is in agreement with Buffetaut et al. (2006) and Buffetaut and Suteethorn (2007) who mentioned resemblances between the vertebrates from the Phu Kradung Formation, such as the crocodilian Sunosuchus and a sinraptorid theropod, and those from the Upper Shaximiao and Shishugou formations of China, which are dated to the Middle Jurassic (Chen et al. 2006) to the Late Jurassic (Dong et al. 1983; Eberth et al. 2001; Lucas 2001; Weishampel et al. 2004). Wang et al. (2003) described Mamenchisaurus sp. from the Penglaizhen Formation, which overlies the Upper Shaximiao Formation. They suggested that Mamenchisaurus was present in China until the latest Jurassic; however, the age of the Mamenchisaurus strata in Sichuan and the neighbouring areas need to be reconsidered (Wang et al. 2003). The age of the Phu Kradung Formation is also controversial: on the basis of vertebrate evidence, Buffetaut et al. (2006) suggested a Upper Jurassic series, whereas palynological evidence suggests a Upper Jurassic to Lower Cretaceous series (Racey and Goodall 2009), based on the occurrence of Dicheiropollis etruscus, which suggests that the Phu Kradung Formation and the overlying Phra Wihan Formation may have been deposited during the Berriasian to Hauterivian stages. Le Loeuff et al. (2002) suggested that the ichnological record of the Phra Wihan Formation shows more similarities with the vertebrate assemblage of the Phu Kradung Formation than with that of the younger Sao Khua Formation. The vertebrate assemblages from the Sao Khua Formation and Phu Kradung Formation are indeed very different (Buffetaut and Suteethorn 2004; Buffetaut et al. 2002,2003,2006; Cavin et al. 2007; Suteethorn et al. 2010).

    Le Loeuff et al. (2002) hypothesized that the main changes in southeast Asian dinosaur assemblages occurred during the Early Cretaceous, after the deposition of the Phra Wihan Formation and before the deposition of the Sao Khua Formation, rather than at the Jurassic-Cretaceous boundary. This might be true for all dinosaur assemblages of Central and Eastern Asia. It seems that the Mamenchisauridae occurred through central, eastern and southeast Asia from the Middle Jurassic to Early Cretaceous (Young and Zhao 1972; Russell and Zhang 1993; Ouyang and Ye 2002; Buffetaut et al. 2005); they would have evolved during a period of geographical isolation caused by the formation of the Turgai Sea between Europe and Asia from the Late Jurassic to the Early Cretaceous (Russell 1993; Barrett et al. 2002; Upchurch et al. 2002). Wilson and Upchurch (2009) hypothesized that Titanosauriformes might have invaded mainland Asia before its isolation since these groups had already appeared in the Middle Jurassic. However, the age of the Mengyin Formation, which has yielded the somphospondylan Euhelopus zdanskyi, is uncertain (Late Jurassic or Early Cretaceous). New informative fossils from the Late Jurassic-Early Cretaceous as well as better correlations between southeast Asian and Chinese localities are needed to better understand the biogeography and evolution of Asian sauropods.

    Acknowledgements

    The senior author thanks Jan Ove Ebbestad (Museum of Evolution, Uppsala, Sweden) for allowing access to specimens in his care. The authors also thank Haiyan Tong (Palaeontological Research and Education Centre, Mahasarakham, Thailand) and Romain Amiot (The Centre National de la Recherche Scientifique, Lyon, France) for providing photographs of several Chinese specimens and Ouyang Hui (Natural History Museum of Chongqing, Chongqing, China) for allowing us to reproduce a photograph of material in his care. We thank Junchang Lu (Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China) and Emilie Läng (Department of Geology and Palaeontology, Muséum d'Histoire Naturelle, Geneva, Switzerland) who provided useful reviews. This study was supported by the University of Mahasarakham (Thailand), the Department of Mineral Resources (Bangkok, Thailand), the TRF-CNRS Special Programme for Biodiversity Research and Training Programme (BRT/ BIOTEC/ NSTDA) Grant BRT R_251175, the Musée des Dinosaures (Espéraza, France), the French Ministry of Foreign Affairs (“Partenariat Hubert Curien” with Thailand), the ECLIPSE Programme of the Centre National de la Recherche Scientifique, a joint project of the Centre National de la Recherche Scientifique and Institut des Sciences de l'Evolution de Montpellier.

    References

    1.

    A. Averianov , A. Starkov , and P. Skutschas 2003. Dinosaurs from the Early Cretaceous Murtoi Formation in Buryatia, Eastern Russia. Journal of Vertebrate Paleontology 23: 586–594. Google Scholar

    2.

    P.M. Barrett and X.L. Wang 2007. Basal titanosauriform (Dinosauria, Sauropoda) teeth from the Lower Cretaceous Yixian Formation of Liaoning Province, China. Palaeoworld 16: 265–271. Google Scholar

    3.

    P.M. Barrett , Y. Hasegawa , M. Manabe , S. Isaji , and H. Matsuoka 2002. Sauropod dinosaurs from the Lower Cretaceous of Eastern Asia: Taxonomic and Biogeographical Implications. Palaeontology 45:1197–1217. Google Scholar

    4.

    M. Borsuk-Bialynicka 1977. A new camarasaurid sauropod Opisthocoelicaudia skarzynskii, gen. n., sp. n. from the Upper Cretaceous of Mongolia. Palaeontologia Polonica 37: 5–64. Google Scholar

    5.

    E. Buffetaut and R. Ingavat 1980. The lower jaw of Sunosuchus thailandicus, a mesosuchian crocodilian from the Jurassic of Thailand. Geobios 13:879–889. Google Scholar

    6.

    E. Buffetaut and V. Suteethorn 1998a. Early Cretaceous dinosaurs from Thailand and their bearing on the early evolution and biogeographical history of some groups of Cretaceous dinosaurs. New Mexico Museum of Natural History and Science Bulletin 14: 205–210. Google Scholar

    7.

    E. Buffetaut and V. Suteethorn 1998b. The biogeographical significance of the Mesozoic vertebrates from Thailand. In : R. Hall and J.D. Holloway (eds.), Biogeography and Geological Evolution of SE Asia , 83–90. Backhuys Publishers, Leiden. Google Scholar

    8.

    E. Buffetaut and V. Suteethorn 2004. Comparative odontology of sauropod dinosaurs from Thailand. Revue de Paléobiologie, Volume Spécial 9: 151–159. Google Scholar

    9.

    E. Buffetaut and V. Suteethorn 2007. A sinraptorid theropod (Dinosauria: Saurischia) from the Phu Kradung Formation of northeastern Thailand. Bulletin de la Société Géologique de France 178: 497–502. Google Scholar

    10.

    E. Buffetaut , V. Suteethorn , and H. Tong 2001. The first thyreophoran dinosaur from Southeast Asia: a stegosaur vertebra from the Late Jurassic Phu Kradung Formation of Thailand. Neues Jahrbuch für Geologie und Palāontologie, Monatshefte 2001 (2): 95–102. Google Scholar

    11.

    E. Buffetaut , H. Tong , and V. Suteethorn 1994. First post-Triassic labyrinthodont amphibian in South-East Asia: a temnospondyl intercentrum from the Jurassic of Thailand. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1994 (7): 385–390. Google Scholar

    12.

    E. Buffetaut , V. Suteethorn , J. Le Loeuff , G. Cuny , H. Tong , and S. Khansubha 2002. A review of the sauropod dinosaurs of Thailand. In : N. Mantajit (ed.), Proceedings of the Symposium on Geology of Thailand, 95–101. Department of Mineral Resources, Bangkok. Google Scholar

    13.

    E. Buffetaut , V. Suteethorn , G. Cuny , S. Khansubha , H. Tong , J. Le Loeuff , and L. Cavin 2003. Dinosaurs in Thailand. In: First International Conference on Palaeontology of Southeast Asia. Mahasarakham University Journal 22 (Special Issue): 69–82. Google Scholar

    14.

    E. Buffetaut , V. Suteethorn , H. Tong , and A. Kosir 2005. First dinosaur from the Shan-Thai Block of SE Asia: a Jurassic sauropod from the southern peninsula of Thailand. Journal of the Geological Society 162: 481–484. Google Scholar

    15.

    E. Buffetaut , V. Suteethorn , and H. Tong 2006. Dinosaur assemblages from Thailand: a comparison with Chinese faunas. In : J. Lu , Y. Kobayashi , D. Huang , and Y. Lee (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium , 19–37. Geological Publishing House, Beijing. Google Scholar

    16.

    J.I. Canudo , J.I. Ruiz-Omeñaca , J.L. Barco , and R. Royo-Torres 2002. Saurripódos asiáticos en el Barremiense inferior (Cretácico Inferior) de España? Ameghiniana 39: 443–452. Google Scholar

    17.

    L. Cavin , U. Deesri , and V. Suteethorn 2007. The holostei fish record (Actinopterygii) from Thailand. In : W. Tantiwanit (ed.), Geothai'07 International Conference on Geology of Thailand: Towards Sustainable Development and Sufficiency Economy , 344–348. Department of Mineral Resouces, Bangkok. Google Scholar

    18.

    P.-J. Chen , J. Li , M. Matsukawa , H. Zhang , Q. Wang , and M.G. Lockley 2006. Geological ages of dinosaur-track-bearing formations in China. Cretaceous Research 27: 22–32. Google Scholar

    19.

    G. Cuny , V. Suteethorn , S. Kamha , K. Lauprasert , P. Srisuk , and E. Buffetaut 2007. The Mesozoic fossil record of sharks in Thailand. In : W. Tantiwanit (ed.), Geothai'07 International Conference on Geology of Thailand: Towards Sustainable Development and Sufficiency Economy , 349–354. Department of Mineral Resouces, Bangkok. Google Scholar

    20.

    Z. Dong , S. Zhou , and Y. Zhang 1983. The dinosaurian remains from Sichuan Basin, China. Palaeontologia Sinica, new series C 23:1–145. Google Scholar

    21.

    D.A. Eberth , D.B. Brinkman , P.-J. Chen , F.-T. Yuan , S.-Z. Wu , G. Li , and X.-S. Cheng 2001. Sequence stratigraphy, paleoclimate patterns, and vertebrate fossil preservation in Jurassic-Cretaceous strata of the Junggar Basin, Xinjiang Autonomous Region, People's Republic of China. Canadian Journal of Earth Science 38: 1627–1644. Google Scholar

    22.

    X. He , K. Li , and K. Cai 1988. The Middle Jurassic dinosaur fauna from Dashanpu, Zigong, Sichuan. Sauropod dinosaur (2). Omeisaums tianfuensis. 143 pp. Sichuan Publishing House of Science and Technology, Chendgu. Google Scholar

    23.

    Y. Horiuchi , K. Hisada , V. Daorerk , S. Imsamut , and P. Charusiri 2008. Meandering River Deposits in the Phu Kradung Formation of the Mesozoic Khorat Group, NE Thailand. In: Proceedings of the International Symposia on Geoscience Resources and Environments of Asian Terranes (GREAT 2008), 356–358. Chulalongkorn University, Chulalongkorn. Google Scholar

    24.

    D.T. Ksepka and M.A. Norell 2006. Erketo ellisoni, a long-necked sauropod from Bor Guvé (Dornogov Aimag, Mongolia). American Museum Novitates 3508: 1–16. Google Scholar

    25.

    J. Le Loeuff 1995. Ampelosaurus atacis (nov. gen., nov. sp.), un nouveau Titanosauridae (Dinosauria, Sauropoda) du Crétacé supérieur de la Haute Vallée de l'Aude (France). Comptes Rendus de l'Académie des Sciences Paris 321: 693–699. Google Scholar

    26.

    J. Le Loeuff , S. Khansubha , E. Buffetaut , V. Suteethorn , H. Tong , and C. Souillat 2002. Dinosaur footprints from the Phra Wihan Formation (Early Cretaceous of Thailand). Comptes Rendus Polevoi 1: 287–292. Google Scholar

    27.

    J. Lü , T. Li , S. Zhong , Q. Ji , and S. Li 2008. A new mamenchisaurid dinosaur from the Middle Jurassic of Yuanmou, Yunnan Province, China. Acta Geologica Sinica 82: 17–26. Google Scholar

    28.

    S.G. Lucas 2001. Chinese Fossil Vertebrates. 375 pp. Columbia University Press, New York. Google Scholar

    29.

    O.C. Marsh 1878. Principal characters of American Jurassic dinosaurs. Pt. I. American Journal of Science 3: 411–416. Google Scholar

    30.

    V. Martin 1994. Baby sauropods from the Sao Khua Formation (Lower Cretaceous) of northeastern Thailand. Gaia 10: 147–153. Google Scholar

    31.

    V. Martin , E. Buffetaut , and V. Suteethorn 1994. A new genus of sauropod dinosaur from the Sao Khua Formation (Late Jurassic or Early Cretaceous) of Northeastern Thailand. Comptes Rendus de l'Académie des Sciences de Paris 319: 1085–1092. Google Scholar

    32.

    V. Martin-Rolland 1999. Les sauropodes chinois. Revue de Paléobiologie, Genève 18:287–315. Google Scholar

    33.

    A. Meesook 2000. Cretaceous environments of Northeastern Thailand. In : H. Okada and N.J. Mateer (eds.), Cretaceous Environments of Asia , 207–223. Elsevier, Amsterdam. Google Scholar

    34.

    A. Meesook , V. Suteethorn , P. Chaodumrong , N. Teerarungsigul , A. Sardsud , and T. Wongprayoon 2002. Mesozoic rocks of Thailand: A summary. In : The Symposium on Geology of Thailand, 82–94. Department of Mineral Resources, Bangkok. Google Scholar

    35.

    H.F. Osborn and C.C. Mook 1921. Camarasaurus,Amphicoelias and other sauropods of Cope. Memoirs of the American Museum of Natural History 3:247–387. Google Scholar

    36.

    H. Ouyang and Y. Ye 2002. The First Mamenchisaurian Skeleton with Complete Skull, Mamenchisaurus youngi. 111 pp. Sichuan Publishing House of Science and Technology, Chengdu. Google Scholar

    37.

    A. Racey and J.G.S. Goodall 2009. Palynology and stratigraphy of the Mesozoic Khorat Group red bed sequences from Thailand. In : E. Buffetaut , G. Cuny , J. Le Loeuff , and V. Suteethorn (eds.), Late Palaeozoic and Mesozoic Ecosystems of Southeast Asia. Geological Society London, Special Publication 315: 69–[83 ] Google Scholar

    38.

    A. Racey , M.A. Love , A.C. Canham , J.G.S. Goodall , S. Polachan , and P.D. Jones 1996. Stratigraphy and reservoir potential of the Mesozoic Khorat Group, NE Thailand. Part 1 : Stratigraphy and sedimentary evolution. Journal of Petroleum Geology 19: 5–40. Google Scholar

    39.

    A.S. Romer 1956. Osteology of the Reptiles. 772 pp. University of Chicago Press, Chicago. Google Scholar

    40.

    D.A. Russell 1993. The role of central Asia in dinosaurian biogeography. Canadian Journal of Earth Science 30: 2002–2012. Google Scholar

    41.

    D.A. Russell and Z. Zheng 1993. A large mamenchisaurid from the Junggar Basin, Xinjiang, People's Republic of China. Canadian Journal of Earth Sciences 30: 2082–2095. Google Scholar

    42.

    D. Schwarz , E. Frey , and C.A. Meyer 2007. Pneumaticity and soft-issue reconstructions in the neck of diplodocid and dicraeosaurid sauropods. Acta Palaeontologica Polonica 52: 167–188. Google Scholar

    43.

    S. Suteethorn , J. Le Loeuff , E. Buffetaut , and V. Suteethorn 2010. Description of topotypes of Phuwiangosaurus sirindhomae, a sauropod from the Sao Khua Formation (Early Cretaceous) of Thailand, and their phylogenetic implications. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 256: 109–121. Google Scholar

    44.

    H. Tong , E. Buffetaut , and V. Suteethorn 2002. Middle Jurassic turtles from southern Thailand. Geological Magazine 139: 687–697. Google Scholar

    45.

    H. Tong , J. Claude , W. Naksri , V. Suteethorn , and E. Buffetaut 2006. Large cryptodiran turtles from the Late Jurassic-basal Cretaceous of Phu Kradung Formation, Khorat Plateau, NE Thailand: a preliminary report. Hantkeniana 5: 109. Google Scholar

    46.

    H. Tong , J. Claude , W. Naksri , V. Suteethorn , E. Buffetaut , S. Khansubha , K. Wongko , and P. Yuangdetkla 2009. Basilochelys macrobios n. gen. and n. sp., a large cryptodiran turtle from the Phu Kradung Formation (latest Jurassic-earliest Cretaceous) of the Khorat Plateau, NE Thailand. In : E. Buffetaut , G. Cuny , J. Le Loeuff , and V. Suteethorn (eds.), Late Palaeozoic and Mesozoic Ecosystems of Southeast Asia. Geological Society London, Special Publication 315: 153–173. Google Scholar

    47.

    P. Upchurch 1995. The evolutionary history of sauropod dinosaurs. Philosophical Transactions of the Royal Society of London, Series B 349: 365–390. Google Scholar

    48.

    P. Upchurch 1998. The phylogenetic relationships of sauropod dinosaurs. Zoological Journal of the Linnean Society 124: 43–103. Google Scholar

    49.

    P. Upchurch , P.M. Barrett , and P. Dodson 2004a. Sauropoda. In : D.B. Weishampel , P. Dodson , and H. Osmólska (eds.), The Dinosauria , second edition, 259–322. University of California Press, Los Angeles. Google Scholar

    50.

    P. Upchurch , C.A. Hunn , and D.B. Norman 2002. An analysis of dinosaurian biogeography: Evidence for the existence of vicariance and dispersal patterns caused by geological events. Proceedings of the Royal Society of London, Series B 269: 613–621. Google Scholar

    51.

    P. Upchurch , Y. Tomida , and P.M. Barrett 2004b. A new specimen of Apatosaurus ajax (Sauropod: Diplodocidae) from the Morrison Formation (Upper Jurassic) of Wyoming, USA. National Science Museum Monographs 26: 1–107. Google Scholar

    52.

    Z.-X. Wang , K. Li , and J. Liu 2003. Mamenchisaurus from Upper Jurassic of Jianyang, Sichuan. Journal of Chengdu University of Technology, Science and Technology Edition 30: 485–490. Google Scholar

    53.

    X. Wang , H. You , Q. Meng , C. Gao , X. Cheng and J. Liu 2007. Dongbeititan dongi, the first sauropod dinosaur from the Lower Cretaceous Jehol Group of Western Liaoning Province, China. Acta Geologica Sinica 81:911–916. Google Scholar

    54.

    M.J. Wedel 2003. The evolution of vertebral pneumaticity in sauropod dinosaurs. Journal of Vertebrate Paleontology 23: 344–357. Google Scholar

    55.

    M.J. Wedel 2009. Evidence for bird-like air sacs in saurischian dinosaurs. Journal of Experimental Zoology 311A: 1–18. Google Scholar

    56.

    M.J. Wedel , R.L. Cifelli , and R.K. Sanders 2000. Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon. Acta Palaeontologica Polonica 45: 343–388. Google Scholar

    57.

    D.B. Weishampel , P.M. Barrett , R.A. Coria , J. Le Loeuff , X. Xu , X. Zhao , A. Sahni , E.M. Gomani , and C.R. Noto 2004. Dinosaur distribution. In : D.B. Weishampel , P. Dodson , and H. Osmólska (eds.), The Dinosauria , second edition, 517–606. University of California Press, Los Angeles. Google Scholar

    58.

    J.A. Wilson 2002. Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnean Society 136: 217–276. Google Scholar

    59.

    J.A. Wilson and P.C. Sereno 1998. Early evolution and higher-lever phylogeny of sauropod dinosaurs. Society of Vertebrate Paleontology, Memoir 5: 1–68. Google Scholar

    60.

    J. A. Wilson and P. Upchurch 2009. Redescription and reassessment of the phylogenetic affinities of Euhelopus zdanskyi (Dinosauria: Sauropoda) from the Early Cretaceous of China. Journal of Systematic Palaeontology 7: 199–239. Google Scholar

    61.

    C. Wiman 1929. Die Kreide-Dinosaurier aus Shantung. Palaeontologia Sinica, Series C 6: 1–67. Google Scholar

    62.

    H. You , D. Li , L. Zhou and Q. Ji 2008. Daxiatitan binglingi: a giant sauropod dinosaur from the Early Cretaceous of China. Gansu Geology 17 (4): 1–10. Google Scholar

    63.

    C.C. Young 1954. On a new sauropod from Yiping, Szechuan, China. Acta Palaeontologica Sinica 3 (4): 481–514. Google Scholar

    64.

    C.C. Young and X. Zhao 1972. Mamenchisaurus hochuanensis, sp. nov. Institute of Vertebrate Paleontology and Paleoanthropology Monograph A 8: 1–30. Google Scholar

    65.

    Y. Zhang , K. Li , and Q. Zeng 1998. A new species of sauropod dinosaur from the Upper Jurassic of Sichuan Basin, China. Journal of Chengdu University of Technology 25: 61–70. Google Scholar
    © 2013 S. Suteethorn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
    Suravech Suteethorn, Jean Le Loeuff, Eric Buffetaut, Varavudh Suteethorn, and Kamonrak Wongko "First Evidence of a Mamenchisaurid Dinosaur from the Upper Jurassic-Lower Cretaceous Phu Kradung Formation of Thailand," Acta Palaeontologica Polonica 58(3), 459-469, (7 February 2012). https://doi.org/10.4202/app.2009.0155
    Received: 3 January 2012; Accepted: 1 January 2012; Published: 7 February 2012
    JOURNAL ARTICLE
    11 PAGES


    SHARE
    ARTICLE IMPACT
    Back to Top