2004

Asiatic Herpetological ResearchVol. 10, pp. 38-52

A Preliminary Report on Southeast Asia’s Oldest Cenozoic Turtle Fauna
from the Late Middle Eocene Pondaung Formation, Myanmar.
J. HOWARD HUTCHISON1, PATRICIA A. HOLROYD1, AND RUSSELL L. CIOCHON2
1Museum of Paleontology, 1101 Valley Life Sciences Building, University of California,

Berkeley, California, 94720, U.S.A.
2Departments of Anthropology and Pediatric Dentistry, University of Iowa, Iowa City, Iowa, 52242, U.S.A.

Abstract. - Late middle Eocene fossils from the Pondaung Formation of central Myanmar document Southeast Asia’s
oldest Cenozoic turtle fauna. Although the material is fragmentary, seven distinct turtle taxa are recognized. These
include a podocnemid pleurodire, anosteirine and carettochelyine carettochelyids, two or more trionychine trionychids, and a testudinid. Of these, only the carettochelyine carettochelyid is complete enough to recognize as a new
taxon, Burmemys magnifica, gen. et sp. nov. The Pondaung turtle fauna is one of the best known of its age fromSoutheast Asia but comparisons with the limited literature of the Eocene faunas from China, Mongolia, and the Indian
subcontinent indicate it is probably biogeographically unique. Among the recognized genera, only Anosteira is known
from other Eocene Asian localities, and the presence of pleurodires is unusual.
Key words. - Reptilia, Testudines, Carettochelyidae, Burmemys, Myanmar, Pondaung Formation, Paleontology,
Eocene.

Introduction
The origins of Southeast Asia’s herpetofauna are poorly
understood, as there are few fossils that document theorigin of the major groups inhabiting the region. The
oldest known herpetofauna from this region is from the
Pondaung Formation, a late middle Eocene (approx. 37
Ma) set of rocks exposed in the Chindwin-Irrawaddy
Basin of Myanmar (formerly Burma). The Pondaung
fauna is best known for its mammalian fauna (e.g.,
Colbert, 1938; Tsubamoto et al., 2000), and little attention has been devoted to the remainder of the fauna. In
prior reports, Buffetaut (1978) noted the presence ofboth unidentified crocodilians and dyrosaurids; Sahni(1984) and Rage (1987) noted unidentified Lacertilia.
These reports were based primarily on a rather limited
collection made by Barnum Brown in 1922 and housedin the American Museum of Natural History, New York.
Savage and Russell (1983) and Broin (1987) list
“Pelomedusid/Emydidae”, “Carettochelyoidea”, and trionychids from the Pondaung. Outside the Pondaungregion, the only other report of turtles from Southeast
Asia is Ducrocq et al.’s (1992) mention of two types of?Emydidae from the late Eocene site of Krabi, Thailand.
Here we present a preliminary description of the turtles
based on a more thorough study of these collections, andadditional collections in the University of California
Museum of Paleontology, Berkeley, California.
Localities and age. - Fossils occur in a number of localities occurring in the upper 100+ meters of the otherwise© 2004 by Asiatic Herpetological Researchmarine Pondaung Formation. The majority of the specimens discussed here come from localities to the west
and northwest of Mogaung village, Myaing Township,
central Myanmar (Fig. 1), that have been collected intermittently over the past 80 years. As a consequence, most
specimens have limited, descriptive locality data thatprovides locations based on distances from known villages. Recent fieldwork has provided detailed, GPS
based mapping of the most productive outcrops and permit us to place most of the historic localities in a moreaccurate and stratigraphically detailed framework.
Those localities we can place with confidence are shownin Figure 1. Localities whose positions are approximate
are shown with dashed lines. Concordances for localities that have been published under more than one nameor number are provided in the caption of Figure 1 andare based on Colbert (1938), maps on file at theAmerican Museum of Natural History, field notes of J.
Wyatt Durham and Donald E. Savage on file at the
University of California Museum of Paleontology, datacontained in Tsubamoto et al. (2000, 2002) and Gunnell
et al. (2002), and field observations by PAH and RLC.
Fossils occur in place and as erosional lag coming
out of reddish to purplish mudstones (Fig. 2 A-C).
Fossil wood is also commonly found (Fig. 2D), attesting
to the presence of the ancient forest. Soe et al. (2002)
interpreted sediments including these localities as swalefills and/or paleosols deposited in an ancient floodplain;stratigraphic sections for these localities are contained in
Gunnell et al. (2002). Based on comparisons of temporal distribution and faunal resemblance data of theVol. 10, p. 39

Asiatic Herpetological Research

92 ° E

96 ° E

2004

MAP 1

100 ° E

22 º N

28 ° N
India

Nyaunggaing
Ch
i nd
win

China
24 ° N

AMNH

16,19
AMNH

14,15,18

Mandalay

Myanmar

Laos

Irra w ad dy

Thandaung

Kadun

V9601220 ° N

Mogaung

V96014

Lema

V83141

V83106

Thailand
Yangon22 º N

MAP 1

AMNH
A31

16 ° N

21 º
50 ' N

V83143

Legan

Monbin2 Km

94 º 45 ' E

Konywa94 º 30 ' E

Mogaung

PALÉ

MAP 2
94º 40 ' E

Legan

ma River
Ya

SinzweChaungzongyi
Sinzwe21 º
45 ' N

Thadut21 º
45 ' N

Paukkaung
Myauktaw

ThadutNyaungma

MAP 2

PK2

PK1

Paukkaung

Bahin

YarshePanganMyauktaw

Bahin

Tanaunggon

Village or Town
Main road
Small roadRiver

MYAING

V6204

10 Km

2 Km

WedaungNandawya

Figure 1. Locality Map of Pondaung Formation localities. V78090=Thandaung kyitchaung and possibly AMNH localities A14-16, 18-19; V83106, 3.5 mi SW of Mogaung = AMNH A31; V83111 "1.25 mi NW Paukkaung" probably equals
Pk2; V83116 probably equals Yarshe kyitchaung. V96001-V96002 = AMNH A22 and Lema kyitchaung; V98019"Thidon or near Bahin", possibly equal to Pk1 or Pk2.

Pondaung mammalian fauna with other Asian and North
American mammal faunas, as well as additional constraining evidence from marine invertebrates, Holroyd
and Ciochon (1994) concluded that the Pondaung fauna
is best considered latest middle Eocene in age andbroadly contemporaneous with Asian faunas assigned to
the Sharamurunian Land Mammal Age, a finding confirmed by recent fission-track dates that provide a dateof 37.2 +/- 1.2 Ma (Tsubamoto et al., 2002).
Abbreviations. - AMNH, American Museum of Natural
History, New York, New York, U.S.A.; UCMP,
University of California Museum of Paleontology,
Berkeley, California, U.S.A.

Systematic Paleontology
Testudines Batsch, 1788
Pleurodira Cope, 1865
Pelomedusoides Cope, 1868
Podocnemididae Cope, 1868
?Podocnemididae unident.
Referred Material. - UCMP locality V83108: UCMP
153798, right peripheral 3. UCMP locality V83113:
UCMP 147052, partial left hypo-xiphiplastron. UCMP
locality V96002: UCMP 142245, left incomplete epiplastron.

2004

Asiatic Herpetological ResearchVol. 10, p. 40

Figure 2. Fossil localities of the Pondaung Formation. A. UCMP locality V96001, Lema kyitchaung; B. UCMP locality V96002, Lema kyitchaung; C-D. UCMP locality V96007, near Mogaung, showing the common occurrence as floatof both turtle bone (C) and petrified wood (D) on the surface.

Description. - The epiplastron (UCMP 142245, Fig.
3A) lacks the posterolateral part but is otherwise wellpreserved. The scale covered surfaces are very finely
textured with delicate but well-defined sulci. Faint
growth corrugations are present on the gular scale(extragular of Hutchison and Bramble, 1981). There is aprominent anteriorly-projecting gular spur, and the epi-

plastron margin is distinctly concave between the midline and the gular spur. There is an intergular scale (gularof Hutchison and Bramble, 1981) spanning the midlinethat projects anteriorly into the anterior embayment. The
scales overlap extensively onto the dorsal surface withlittle exposure of the visceral surface. The intergularexpands slightly posteriorly on the ventral surface andVol. 10, p. 41

Asiatic Herpetological Research

2004

Figure 3. A-C. Podocnemidae? indet. A. UCMP 142245, incomplete left epiplastron, dorsal, medial suture and ventral views. B. 153798, right peripheral 3, external and visceral views. C.UCMP 147052, hypo-xiphiplastron fragment,
dorsal view, spot indicates center of bump. D-E. Testudinidae. D. UCMP 142226, partial right epiplastron, cross-section (as indicated) and dorsal views. E. UCMP 149166, partial right xiphiplastron, dorsal view. Scale bars equal 1 cm.

extends onto the entoplastron. Dorsally the intergularextends slightly more than one-half the length of theinter-epiplastral suture and is parallel-sided. On the ventral surface, the gular is triangular with the lateral margins converging to a point at the entoplastron margin.
The hypo-xiphiplastron fragment, UCMP 147052(Fig. 3C), is broken on all the edges except the free margin. It exhibits a narrow overlap of the femoral and anal
scales onto the dorsal surface (less than one-fifth thetransverse length as preserved). The swelling at theanterolateral corner indicates an ascendant hypoplastral
buttress. The sutures are fused. A short expanse of thefemoral-anal scale sulcus is preserved at the extreme
posterior end. Medial to the scale margins on the dorsalside is a large elliptical swelling that has a smooth surface and may have been divided by the hypo-xiphiplastron suture.
The peripheral 3 (UCMP 153798, Fig. 3B) lacks thedorsal margin. The body of the peripheral is robust andwithout a change in plane between the pleural and marginal surfaces. The surface is smooth and unsculptured.
The sulci are shallow but well defined. The free margin
is acutely angled. On the visceral side, the marginal
scales rise up from only about one-third of the peripheral depth. There is no indication of an axillary scale. The

finely dentate suture for the hyoplastron buttress rises
anteriorly and may have overlapped peripheral 2-3
suture. There is a gap in the hyoplastral suture near theposterior margin, for passage of the musk duct. The
length between the anterior and posterior sutures along
the free margin of the peripheral is 37.9 mm.
Discussion. - The dorsal scale overlap, truncated anterior margin, undivided intergular, and relatively thick epiplastra resemble selected extant or fossil
Pelomedusoides (Bothremydiae, Podocnemididae, andPelomedusidae). The prominent epiplastral spurs resemble those of the pelomedusid Kenyemys Wood, 1983,
from the Pliocene of Kenya. However, the Pondaung
form differs in the greater excavation of the gular
embayment, intergular extending onto the entoplastron,and restriction of the gular scales to the epiplastra (i.e.,
not reaching the midline). The scale arrangement is similar to that of the podocnemidid Neochelys Bergounioux,1954 (Broin, 1977; Jimènez et al., 1994) from the
Eocene of Europe. Neochelys may also possess a relatively prominent gular spur (Broin, 1977, fig. 59), butdiffers in the less extensive dorsal overlap of the scales
and lesser development of an epiplastral embayment.

2004

Asiatic Herpetological ResearchVol. 10, p. 42

Figure 4. Anosteira sp., A. UCMP 131736, right hypoplastron, ventral view. B. UCMP 131737, lateral fragment of left
hypoplastron, ventral view. C. UCMP 147030, left peripheral 6, external, posterior, visceral, and anterior views. Scalebars equals 1 cm.

The presence of a prominent musk duct on the
peripheral 3, absence of an axillary scale, and strong
indication of a hyoplastral buttress rising onto the first
costal is consistent with Neochelys-like pleurodires. The
hypoplastron fragment may be referable to the sametaxon, but the area of the pelvic sutures is broken off.
The general similarity to at least some Neochelys
favors a placement of the Pondaung Formation specimens in the Podocnemididae.
Cryptodira Cope, 1868
Testudinidae Gray, 1825
Testudinidae undet.
Referred Material. - UCMP locality V6204: UCMP
149166, right xiphiplastron fragment. UCMP locality
V96009: UCMP 142226, partial right epiplatron.

(UCMP 149166, Fig. 3E) is referred to the Testudinidae
on the basis of the strong overlap of the femoral scaledorsally, its inflated appearance, and fairly porous surface texture.
Discussion. - The morphology of the epiplastron is typical of testudinids and a few batagurids. The rather
porous bone, inflation of the gular area, and generalnature of the sutures and surface texture agrees best withthat of a testudinid. The overhang of the posterior gular
rim is derived in testudinids and absent or poorly developed in such tortoises as Hadrianus Cope, 1872,
Stylemys Leidy, 1851, Sharemys Gilmore, 1931,
Kansuchelys Yeh, 1963, and Ergilemys Ckhikvadze,1972. The epiplastron thus resembles more derived tortoises such as Testudo Linnaeus, 1858.
Testudinoidea Fitzinger, 1826, indet.

Description. - The epiplastron (UCMP 142226, Fig.
3D) lacks the gular region. The remaining part of thefree margin is greatly thickened along the anterior edgeof the dorsal scale covered portion. The posterior rim of
this thickened gular area overhangs the visceral surface.
The ventral surface is longitudinally convex. The
sutures are moderately thick and dentate.
The anterolateral part of a right xiphiplastron

Referred material. - UCMP locality V96019: UCMP
147051, posterior part of left hypoplastron. UCMP
locality V78090: UCMP 170495, partial neural. UCMP
locality V98109: UCMP 170522, shell fragments.
Description. - The hypoplastron is represented by afragment (UCMP 147052) that preserves the portion

Vol. 10, p. 43

Asiatic Herpetological Research

2004

Figure 5. Burmemys magnifica gen. et sp. n. A. UCMP 61212, adult left hypoplastron (type), ventral view. B. UCMP
131745. juvenile left hypoplastron, ventral view. C. UCMP 154993, posterior part of juvenile left epiplastron, ventral
view. D. UCMP 131747, anterior part of juvenile left xiphiplastron, dorsal and ventral view. E. UCMP 157444, juvenile
left costal 2, external view. F. UCMP 147022, neural, external view. G. UCMP 157442, suprapygal, external view. Scalebars equals 1 cm.

2004

Asiatic Herpetological ResearchVol. 10, p. 44

Figure 6. Burmemys magnifica gen. et sp. n. A. AMNH 14196, left peripheral 1, anterior suture, external and visceralviews. B. UCMP 147021, left peripheral 1, external, posterior suture and visceral views. C. UCMP 147027, left peripheral 2, external and visceral views. D. UCMP 147002, left peripheral 3, external, visceral and posterior suture views.
E. UCMP 61211, left peripheral 4, external and visceral views. F. UCMP 147001, left peripheral 4 fragment, visceraland posterior suture views (arrow points to flat hyoplastral suture). G. UCMP 131756, juvenile left peripheral 5, suture
view. H. UCMP 61218, left peripheral 6, external, posterior suture, visceral and anterior suture views. I. UCMP 142223,
right peripheral 7, external, anterior suture, visceral, posterior suture views. J. UCMP 157445, juvenile left peripheral
7, external, visceral, and anterior suture views. K. UCMP 142244, right peripheral 8, external, anterior suture, visceral and posterior views. L. AMNH 1911, left peripheral 10 and pygal, external view. Scale bars equal 1 cm.

Vol. 10, p. 45

Asiatic Herpetological Research

posterior to the buttress. The free margin is slightly convex. The femoral scale distinctly but narrowly overlaps
the dorsal side. The margin dorsal margin of the scale ismarked by a shallow sulcus and the bone continues tothicken medially before thing nearer the midline. A partial neural (UCMP 170495) has a distinct carina with arounded top.
Discussion. - The referred fragmentary specimens do
not appear to belong to other known taxa in the fauna
and agree in general morphology with testudinoids,
probably testudinids or batagurids. The neural resembles
those of carinate batagurids.
Carettochelyidae Boulenger, 1887
Anosteirinae Lydekker, 1889
Anosteira Leidy, 1871
Anosteira sp.
Referred material. - UCMP locality UCMP V78090:
UCMP 131752, peripheral 9 or 10; UCMP 131754,
hypoplastron fragment; UCMP 131755, posterior fragment of nuchal; UCMP 147115, neural. UCMP locality
V83106: UCMP 131736, medial right hypoplastronfragment; UCMP 131737, lateral hypoplastron fragment; UCMP 131741, peripheral 7; UCMP 131742,
peripheral 8; UCMP 131744, costal fragments; UCMP
131746, anterior fragment of a right peripheral 6. UCMP
locality V96001: UCMP 147005, hypoplastron fragment; UCMP 147011, left peripheral 7. UCMP locality
V96002: UCMP 147030, left peripheral 6. UCMP locality V96008: UCMP 147024, right peripheral 2. UCMP
locality V96009: UCMP 142225, peripheral 9 or 10.
Description: The hyoplastron resembles those seen in
typical Anosteira and Pseudanosteira Clark, 1932, andlacks the truncated anteromedial articulation of the new
genus described below. This specimen differs from
Allaeochelys Noulet, 1867, in having a narrower posterior lobe and narrower bridge area.
The peripherals are referred to Anosteira on thebasis of their small size and well-formed sutures. Most
also show the presence of weekly-defined sulci on theexternal surface. All the peripherals have sharp marginal carina, and the surface is finely pustulate. The gomphotic pits for reception of the plastron on peripheral 6(UCMP 147030, Fig. 4C) lie within a longitudinal
trough that traverses the peripheral. The latter is 12.6mm along the free margin carina and 12.5 mm from thecarina to the costal suture. A partial peripheral 6 (UCMP
131746) has the trough on the plastral suture filled with
8-9 vertically elongated pits and a sharp lateral carina.
The two gomphotic pits on peripheral 7 also occur within a trough, but on peripheral 7 the trough is only
approximately two-thirds the length of the bone. The

2004

peripheral 7 (UCMP 147011) is 12.0 mm along the carina. The specimen tentatively identified as peripheral 9 or
10 (UCMP 131752) is deeper than long (16 mm along
the margin, 18 mm in depth).
The posterior nuchal fragment has the typical carettochelyid nuchal pedicle. A faint transverse sulcus ispresent, and another faint longitudinal sulcus near the
midline is visible.
A small neural (UCMP 147115) is also referred toAnosteira on the basis of the small size and patterned
surface, narrow length to width ratio, and low and broadcentral carina.
Discussion. - Anosteira is known from both Asia (5species) and North America (1 species) in the Eocene.
The closely related genus Pseudanosteira is limited to
North America and distinguishable from Anosteira only
by details of the top of the carapace. No elements in the
Pondaung collection resemble Pseudanosteira. The
presence of sulci on the peripherals, nuchal, and costal
fragments indicates it should be assigned to Anosteira.
The Pondaung specimen is most parsimoniously
referred to Anosteira in the absence of any evidence that
Pseudanosteira occurs anywhere in Asia. Previous
records of Anosteira are confined to China andMongolia.
Carettochelyinae Boulenger, 1887
Burmemys magnifica gen. et sp. nov.
Holotype. - UCMP 61212, adult left hypoplastron (Fig.
5A) from UCMP Locality V6204 (near Myaing), foundby J. Wyatt Durham, late Professor of Paleontology at
the University of California, Berkeley.
Paratypes. - AMNH locality “1 mile northeast of Gyat,
Magwe Province”: AMNH 1911, pygal, peripheral 10
fragment, and costal fragment. AMNH locality “1 mile
north of Koniwa”: AMNH 1919, left first peripheral;
AMNH 1928, distal half of right first peripheral; AMNH
14196, partial left peripheral 1; AMNH 14197, plastronfragment. UCMP locality V6204: UCMP 61211, left
peripheral 4; UCMP 61218, left peripheral 6. UCMP
locality V78090: UCMP 131750, juvenile lateralhypoplastron fragment, UCMP 131751, juvenile peripheral fragment; UCMP 131753 juvenile xiphiplastronfragment; UCMP 154994, proximal costal fragment.
UCMP locality V83106: UCMP 131738, juvenile righthypoplastron; UCMP 131739, juvenile hypoplastronfragment; UCMP 131745, juvenile left hypoplastron.
UCMP locality V83111: UCMP 128406, right peripheral 2. UCMP locality V83116: UCMP 131748, hypoplastron fragment. UCMP locality V83143: UCMP 131747,

Vol. 10, p. 46

Asiatic Herpetological Researchanterior part of left xiphiplastron. UCMP locality
V96001: UCMP 147001, left peripheral 4 fragment;
UCMP 147002, partial left peripheral 3; UCMP 147003,
anterior peripheral fragment; UCMP 147009, neural;
UCMP 147010, peripheral fragment; UCMP 147012,
juvenile medial hypoplastron fragment. UCMP locality
V96002: UCMP 142244, right peripheral 8; UCMP
154984, anterior peripheral fragment. UCMP locality
V96008: UCMP 147021, left first peripheral; UCMP
147023, posterior peripheral fragment; UCMP 147027,
left peripheral 2; UCMP 147028, partial right peripheral
1; UCMP 147029 distal fragment of a costal. UCMP
locality V96009: UCMP 142223, right peripheral 7.
UCMP locality V99498: UCMP 157443, neural; UCMP
157446, shell fragments.
Referred material. - UCMP locality V96001: UCMP
147004, plastron fragment. UCMP locality V83106:
UCMP 131740, hyoplastron fragment. UCMP locality
V78090: UCMP 131756, juvenile left peripheral 5;
UCMP 154993, posterior fragment of left epiplastron.
UCMP locality V99498: UCMP 157442, suprapygal;
UCMP 157444, left costal 2; UCMP 157445, left peripheral 7.
Diagnosis. - Burmemys is distinguished from othercarettochelyines by the combination of asymmetrical
articulation of the hyo-hypoplastra, narrow hypoplastralbridge, and large size (estimated carapace length greaterthan 1000 mm).
Description. - The holotype hypoplastron (UCMP
61212, Fig. 5A) is massive. The anterior suture of theleft hypoplastron consists of two sutures. The suturewith the left hyoplastron is sinusoidal, curving anteromedially, and joins a distinct, straight and anteromedially-facing suture, presumably for articulation with theright hyoplastron. The ventral sculpture consists of apattern of irregular, closely-spaced tubercles that radiatefrom a focal point lateral to the middle of the medial
moiety. Laterally, the tubercles coalesce into ridges radiating laterally. The sutures are finely dentate and thick(13 mm). The lateral margin and posterior half of themedial part is broken away in the type, but these are preserved in the juvenile specimen (UCMP 131745, Fig.
5B). The width of the medial part of the hypoplastronmeasured from the apex of the inguinal notch to theplastral midline is only one-half or less of the maximum
hypoplastral width. The inguinal notch is open and notconfined as in Carettochelys Ramsey, 1887. The anterior-posterior width of the bridge area is one-half or lessthe width of the xiphiplastral lobe of the hypoplastron.
The referred juvenile specimens exhibit the same sutur-

2004

al shapes as the adult (type) but the inguinal notches areshallower, sculpture less organized, and lateral extent of
the lateral arm of the bridges are shorter.
The posterior part of a juvenile epiplastron (UCMP
154993, Fig. 5C) is referred to Burmemys on the basis of
the convex curvature of the lateral margin that indicatesa short and rounded anterior lobe, and an obtuse angle
between the entoplastral and hyoplastral sutures indicating a short and broad entoplastron.
Two xiphiplastra (UCMP 131747, Fig. 5D; UCMP
131753) are referred to Burmemys on the basis of relatively larger size, converging (non-parallel) medial andlateral margins of the anterior moiety, and thinning
rather than thickening toward the midline suture. Bothspecimens are small (proximal width of UCMP 131747
is 20 mm) and thus considered as juveniles.
The juvenile left costal (UCMP 157444, Fig. 5E) is
nearly uniformly thin, parallel sided, and sculptured
with a subdued and random pattern of low pustules andshort ridges. The distal margin forms about a 45 degree
angle to the sides. There are no sulci. The parallel sides
and high angle of the distal margin indicate a second
costal.
The distal end of an adult costal (UCMP 147029) is
subtlety sculptured with longitudinal irregular ridges.
The distal suture is weakly dentate but patent except
above the rib. The rib ends protrudes prominently.
Although damaged, the distal width is about 70 mm.
A large neural (UCMP 147009, Figs. 5F) is relatively narrow, lacks a midline carina, and has subtle sculpture of very shallow dimples. It has a midline length of
51 mm, maximum width of 32 mm, and maximum
thickness of the lateral side of 15.4 mm.
The suprapygal (UCMP 157442, Fig. 5G) is triangular with a distinct medial carina. The surface sculpture
consists of irregular vermiform ridges that radiate fromthe central area of the posterior margin. It is longer thanwide (32.2 mm long, 31.5 mm wide).
At least nine peripheral positions are represented.
The sculpture is variable consisting of distinct tubercles
at one extreme to anastomosing pits and ridges at theother. The free margins of adult specimens are rounded
but may be acute in juveniles. There are no indicationsof scale sulci.
The first peripheral exhibits distinct sutures with thefirst costal, nuchal and second peripheral. The free margin perimeter is asymmetrically curved. The largest
specimens (AMNH 1919, Fig. 6A; UCMP 147021, Fig.
6B) have perimeter lengths of 114 and 119 mm, maximum depths of 90 and 81 mm, maximum thicknesses atthe posterior suture of 33 and 27 mm, and maximum
thicknesses at anterior suture of 28 and 25 mm respectively.

2004

Asiatic Herpetological Research

The two second peripherals differ in size. UCMP
147026 (Fig. 6C) is massive with a free margin length of
82 mm, maximum depth of 67 mm, and maximum thickness of the anterior suture of 20 mm. Comparable measurements of UCMP 128406 are 45, 40, and 11 mm
respectively. The second peripheral is roughly rectangular in external view.
The only specimen referred to the third peripheral(UCMP 147002, Fig. 6D) is lacking the anteroventral
and posterodorsal corners. The anterior part of the dorsal suture is a semi-scarf joint – probably for the rib endof the first costal. The peripheral thickens noticeably
towards the posterior suture and reaches a thickness of
32 mm at the suture.
The fourth peripheral (UCMP 61211, Fig. 6E) isdamaged anteriorly and dorsally and locally abraded. Its
length along the lateral carina is 75 mm. The free margin curves posteromedially on the posterior moiety toform a plastral articulation. The plastral articular surface
is relatively flat but deep (up to 16 mm) and without pits
for the hyoplastral buttress or normal dentations, thus
indicating a weakly ligamental and kinetic joint. The lateral carina is broadly rounded. The peripheral 4 fragment (UCMP 147001, Fig. 6F) also shows this rather flatand deep (19 mm) hyoplastral suture.
A small peripheral, probably a left peripheral 5(UCMP 131756, Fig. 6G) is considered a juvenile of thisspecies. The plastral arm is very short with a longitudinal trough enclosing a series of gomphotic pits. The lateral carina is slightly rounded and broadly upturned. The
length of the lateral carina is 22 mm and has a posterior
thickness of about 9 mm.
A relatively complete left peripheral 6 (UCMP
61218, Fig. 6H) has a damaged plastral margin and lacks
the dorsal suture. The plastral and costal arms converge
posteriorly. The plastral articulation is broken anteriorly
but posteriorly has a longitudinal trough indicating interdigitation with the hypoplastron. The lateral carina isrounded and slightly upturned. The length along the lateral carina is 82 mm.
A peripheral 7 (UCMP 142223, Fig. 6I) of an adultmeasures 99 mm along the marginal carina, 100 mm
from the carina to costal margin, posterior thickness of
29 mm and an anterior thickness of more than 45 mm.
The hypoplastral suture is damaged but trough-like,
extends about half-way along the medial side, andappears to have housed one or two recessed pits. The
isolated peripheral 7 (UCMP 157445, Fig. 6J), a presumed juvenile, closely resembles Carettochelys withthe hypoplastral buttress rising up the central part of themedial side. The free margin is sharp and broadly
upturned. The length of the free margin is about 34 mm.
The adult peripheral 8 (UCMP 142244, Fig. 6K) is
massive and slightly shorter than deep (97 mm along thelateral carina and 105 mm from the carina to costal

Vol. 10, p. 47

suture). An anteriorly-deepening trough divides themedial surface into dorsal and ventral arms anteriorly.
The pygal (AMNH 1911, Fig. 6L) is distinctly
trapezoidal with a short anterior side and a low but sharp
medial crest. The sculpture consists of widely spaced
irregular tubercles that fade out near the medial crest andfree margin. An associated posterior peripheral 10 fragment has a sculpture of irregular ridges and tubercles
that radial from a central focus.
Discussion. - The absence of scales and large size place
Burmemys in the Carettochelyinae. Of the three Eocene
genera of Carettochelyinae, Burmemys differs from allin the presence of two distinct anterior articular sutures
on one of the hypoplastra. This most likely represents anasymmetrical articulation with the hyoplastra, with oneof the hyoplastra extending well across the midline toform an angled articulation with the opposite hypoplastron. Even where the hyo-and hypoplastra are not mirror
images with one of the hypoplastra contacting the opposite hyoplastron (e.g., Anosteira in Hay, 1908, Fig. 353),
the midline suture remains straight as in other Paleogene
carettochelyids and the plastral midline suture usuallyexhibits some limited kinesis. This asymmetry is not
unusual in turtles, but within carettochelyids was known
only to a lesser degree in some Carettochelys. The
hypoplastron in extant Carettochelys insculpta Ramsey,1887 may cross the midline to form a short angled suturewith the opposite hyoplastron (AMNH 84212, andRooij, 1915, fig. 123a). This occurs on the left hyoplastra on both of these.
Burmemys resembles anosteirines and differs fromextant Carettochelys, Hemichelys Lydekker, 1887, (pl.
XII, fig. 2) from the Eocene of the Punjab, andChorlakkichelys Broin, 1987 (pl. 1, fig. 2) from the
Eocene of Pakistan in the relatively broad inguinal
notch. Burmemys additionally differs from
Chorlakkichelys and Carettochelys in having a distinctly narrow bridge area. The general proportions of the
hypoplastron resemble those of Allaeochelys from the
Eocene of Europe (Broin, 1977, Pl. XV1, Fig. 3). The
suprapygal differs from Allaeochelys, Carettochelys,
Hemichelys and probably Chorlakkichelys in being
longer than wide.
Burmemys is also the largest carettochelyid
described to date. Based on scaling up of the elements
in comparison to other carettochelyids, we can estimatethat the shell length of Burmemys exceeded 1000 mm.
This estimate suggests that Burmemys is among thelargest turtles known, but is smaller than estimates Headet al. (1999) provided for Eocene trionychids from
Pakistan, which may have reached more than 2000 mm
in length, and is smaller than the giant Bridgerian trionychid from Wyoming (Gaffney, 1979).

Vol. 10, p. 48

Asiatic Herpetological Research

2004

Figure 7. Trionychinae. A. UCMP 61213, right hypoplastron, ventral view. B. UCMP 1537993, fragment of righthypoplastron, ventral view. C. UCMP 147022, neural, external view. D. UCMP 170520, costal fragment, external view.
Scale bars equals 1 cm.

Trionychidae Gray, 1825
Trionychinae Gray, 1825
Trionychinae genus indet.
Trionychinae, large form
Referred material. - UCMP locality V6204: UCMP
61213, right hypoplastron. UCMP locality V78090:
UCMP 170497, costal fragments. UCMP locality
V83116: UCMP 153799, fragment of right hypoplastron. UCMP locality V83143: UCMP 173809, plastronfragment. UCMP locality V96001: UCMP 147020,
costal fragment. UCMP locality V96002: UCMP
154983, costal proximal fragment. UCMP locality
V96008: UCMP 147022, neural. UCMP locality
V96009: UCMP 142222, plastron fragment.

into three fluted points at its tip.
The isolated neural (UCMP 147022, Fig. 7C), probably 6 or 7, is hexagonal and narrows distinctly posteriorly. The dorsal surface is weakly sculptured, lack sulci,
and is flat anteriorly but is formed into a central carina
posteriorly. The neural is 46 mm long and 50 mm wide.
Discussion. - The large size of the hypoplastron andgeneral conformation indicates a trionychine and generally resembles Pelochelys Gray 1864, Chitra Gray 1844,
and Pelodiscus Fitzinger 1835 in these features, but differs in having a wide, unsculptured medial shelf.
Additional material would be needed to refine identification.
Trionychinae, small form

Description. - The hypoplastron (UCMP 61213, Fig.
7A) lacks the projecting spines (present in UCMP
153799, Fig. 7B) but is otherwise relatively complete.
The calloused area has well defined edges and covers
most of the ventral surface, except for the long offset
shelf on the medial edge. The calloused area is sculptured with distinct pits and ridges, while the shelf isamorphously roughened. The buttress is composed of
two protruding spikes. The posteromost of these is broken off at the base, but the larger anterior one is divided

Referred material. - UCMP locality V6204: UCMP
61210 plastron fragment. UCMP locality V83106:
UCMP 147116, two costal fragments.
Description. - Two distal costal fragments exhibit awell-defined sculpture of pits and ridges with indications of longitudinal welts. The pattern extends to thefree margin with only a slight sculpture-free zone at thefree margin, suggesting an adult turtle of relatively small

2004

Asiatic Herpetological Research

size in comparison with the preceding taxon. The sculpture resembles that of a trionychine rather than acyclanorbine such as Lissemys Smith, 1931.
Trionychinae, ornate form
Referred material. - UCMP locality V98109: UCMP
170520, two costal fragments.
Description. - The costal fragments (UCMP 170520,
Fig. 7D) exhibit a striking sculpture of large, elongate
tubercles rising above a surface composed of a generally organized pattern of longitudinal rows of shallow pits
and low rides. The longitudinal axes of the raised tubercles vary from anterior-posterior to medial-lateral andare large (11-15 mm) relative to the overall size of thelarger costal fragment (maximum preserved width of 32mm). Carapace sculpturing varies between individuals
and also ontogenetically, but the peculiar sculpture
shows some resemblance to that seen in some extant
Aspideretes Hay, 1904.

Discussion
In addition to the turtles, a variety of other lower vertebrates are present in the Pondaung Formation including
a carcharhinid shark, Galeocerdo Müller and Henle
1837 (UCMP 142238), a clariid catfish (UCMP
128411), at least four species of agamid lizards (UCMP
128410, 130290, 142227, 142232), paleophid and colubroid snakes (see Head et al, in prep.), and a minimumof two crocodilians, including a pristichampsine crocodylian (UCMP 147127) and a dyrosaurid (Buffetaut,1978).
Unfortunately, reports on Asian lower vertebrates ofcomparable age (Sharamurunian Asian Land Mammal
Age or late middle Eocene) are few. Thus, the limited literature, combined with the fragmentary nature of the
Pondaung fossils themselves, make detailed comparisons with other faunas difficult. Nonetheless, comparisons with known Sharamurunian lower vertebrate faunas reveal only a few similarities between the Pondaungand any other locality. Pleurodires are previously undescribed from Asia, although Broin (1987) notes the presence of “Pelomedusidae and/ or Emydidae” from the
middle Eocene of Pakistan and Oligocene of India. An
adocid was described by Gilmore (1931) from the late
middle Eocene of Mongolia, but none were identified in
the Pondaung assemblage. The carettochelyid genus,
Anosteira, has been reported from age-equivalents in
Manchuria (Zangerl, 1947) and Guangdong, China (Sun
Ailing et al., 1992) and from slightly younger sediments
in Shandong and Guangdong provinces (Yeh, 1963).
The only other carettochelyines described from Asia are

Vol. 10, p. 49

Chorlakkichelys and Hemichelys from the early middle
Eocene of Pakistan (Lydekker, 1887; Broin, 1987), andBurmemys is the most easterly and southerly Eocene
record of the subfamily. Trionychids, as elsewhere, are
an important part of the fauna, but our material is not
sufficiently diagnostic to make any meaningful biogeographic comparisons. Testudinids are widely reported in
Chinese and Mongolian Eocene faunas (Gilmore, 1931;
Ye, 1963), but all of these appear to be more generalized
forms similar to Hadrianus or Kansuchelys. The
Pondaung form appears to be more like the modern
Testudo, and thus distinct from contemporaneous
Chinese and Mongolian taxa.
Among other reptiles, the only other agamid lizard
known in the Asian Sharamurunian is Tinosaurus yuanquensis from the Heti Formation (Li, 1991), but it is adiminutive form that bears no resemblance to the
Pondaung agamids. Crocodilians are known elsewhere,
but not in detail. In overall diversity, the Pondaung
fauna shares more general resemblances to the betterknown Irdinmanhan faunas, especially that of theKuldana Formation of Pakistan (Broin, 1987).
Based on the fragmentary evidence available todate, several observations can be made regarding the
Pondaung lower vertebrate fauna. Faunal endemicity is
supported by the number of unique taxa, and the composition of the turtle fauna is unusual with trionychoids(especially carettochelyids) dominating. Faunal composition and the large size of these turtles are consistent
with an interpretation of these sites as representing a
warm, tropical floodplain environment, deposited fairly
near shore. The aquatic habits of most of the lower vertebrates suggest that during late middle Eocene time the
Pondaung region was a well-drained floodplain environment, a finding consistent with previous geologicalinterpretations (e.g., Bender, 1983, Soe et al., 2002).

Acknowledgments
We are grateful to Donald E. Savage, Ba Maw, andThaw Tint for reinitiating fieldwork in the Pondaungregion in the late 1970’s, and Brig.-Gen Than Tun and
Major Bo Bo from the Office of Strategic Studies,
Ministry of Defense for arranging our visits to
Myanmar. Tin Thein, Aye Ko Aung, Aung Naing Soe,and other members of the Pondaung Fossil Expeditionteam are thanked for their assistance during our stays
and their help while in the field. Eugene Gaffney,Charlotte Hotton, and Mark Norell kindly provided
access to and assistance in use of the AMNH collections
and associated records. Walter Joyce reviewed the manuscript and provided constructive criticisms. Funding
for fieldwork in Myanmar has been provided by theSmithsonian Foreign Currency Program (from PublicVol. 10, p. 50

Asiatic Herpetological Research

Law 480 funds), the L.S.B. Leakey Foundation, theUniversity of California Museum of Paleontology, theUniversity of North Carolina at Charlotte Foundation,
the University of Iowa Center for Pacific and AsianStudies, the Office of the Vice President for Researchand the Human Evolution Research Fund of the
University of Iowa Foundation. This is UCMP contribution no. 1836.

Literature Cited
Batsch, A. J. G. C. 1788. Versuch einer Anleitung zur
Kenntniss und Geschichte der Thiere undMineralien. Vol. 1. Akademische Buchhandlung,
Jena. viii + 528 pp.
Bender, F. 1983. The Geology of Burma. Beiträge zur
Regionalen Geologie der Erde, Band 16, 293 pp.
Boulenger, G. A. 1887. On a new family of pleurodiranturtles. Annals and Magazine of Natural History
19:170-172.
Broin, F. de. 1977. Contribution à l’étude deschéloniens. Chéloniens continentaux du Crétacé etdu Tertiaire de France. Mémoires du Muséum
National d’Histoire Naturelle, N. Ser. C, 38:1-423.
Broin, F. de. 1987. Lower vertebrates from the earlymiddle Eocene Kuldana Formation of Kohat(Pakistan): Chelonia. Contributions from theMuseum of Paleontology, University of Michigan
27(7):169-185.
Buffetaut, E. 1978. A dyrosaurid (Crocodilia,
Mesosuchia) from the upper Eocene of Burma.
Neues Jahrbuch für Geologie und Paläontologie,
Monatshefte 5:273-281.
Ckhikvadze, V. M. 1972. O sistematichekom polozhenii
tretichnykh gigantskikh sukhoputnykh cherepakh
Palearktiki. [On the systematic positions of the
Tertiary gigantic land turtles of Palearctic]. Bulletinof the Academy of Sciences of the Georgian R.S.S.
65(3):745-748.

2004

Cope, E D. 1865. Third contribution to the herpetologyof tropical America. Proceedings of the Academy of
Natural Sciences of Philadelphia 1865:185-198.
Cope, E D. 1868. On the origin of genera. Proceedingsof the Academy of Natural Sciences, Philadelphia
1868:92-93.
Cope, E. D. 1872. Second account of new vertebratafrom the Bridger Eocene of Wyoming Territory.
Proceeding of the American Philosophical Society
12:466-468.
De Rooij, N. 1915. Reptiles of the Indo-AustralianArchipelago, Lacertilia, Chelonia, Emydosauria. E.
J. Brill, Leiden. 1: xiv + 384 pp.
Ducrocq, S., E. Buffetaut, H. Buffetaut-Tong, R.
Helmcke-Ingavat,
J.-J.
Jaeger,Y.
Jongkanjanasoontorn, and V. Suteethorn. 1992. A
Lower Tertiary vertebrate fauna from Krabi (South
Thailand). Neues Jahrbuch für Geologie undPaläontologie, Abhandlungen 184(1): 101-122.
Fitzinger, L. J. 1826. Neue Classification der Reptilien
nach ihren natürlichen Verwandtschaften nebst
einer
Verwandtschafts-Tafel
und
einen
Verzeichnisse der Reptilien-Sammlung des k. k.
Zoologischen Museum’s zu Wien. J. G. Hübner,
Wien, viii + 66 p.
Fitzinger, L., 1835. Entwurf einer systematischen
Anordnung der Schildkröten nach den Grundsätzen
der natürlichen Methode. Annalen der Wiener
Museums des Naturgeschichte 1:103-128.
Gilmore, C. W. 1931. Fossil turtles of Mongolia.
Bulletin of the American Museum of Natural
History 59:213-257.
Gray, J. E. 1825. A synopsis of the genera of reptiles andAmphibia, with a description of some new species.
Annals of Philosophy, London. Ser. 2 10:193-217.

Clark, J. 1932. A new anosteirid from the Uinta Eocene.
Annals of the Carnegie Museum 21:161-170.

Gray, J. E. 1844. Catalogue of tortoises, crocodiliens,and amphisbaenians in the collection of the British
Museum. British Museum (Natural History),
London. viii + 80 pp.

Colbert, E. 1938. Fossil mammals from Burma in theAmerican Museum of Natural History. Bulletin of
the American Museum of Natural History 74:255436.

Gray, J. E. 1864. Revision of the species Trionychidae
found in Asia and Africa, with description of somenew species. Proceedings of the Zoological Societyof London 1864: 76-98.

2004

Asiatic Herpetological Research

Gunnell, G. F., R. L. Ciochon, P. D. Gingerich, and P. A.
Holroyd. 2002. Re-assessment of Pondaungia andAmphipithecus (Primates) from the late middle
Eocene of Myanmar with comments on“Amphipithecidae.”Contributions from theMuseum of Paleontology, University of Michigan
30: 337-372.
Hay, O. P. 1904. On the existing genera of theTrionychidae. Proceedings of the Americana
Philosophical Society 42:268-249.
Hay, O. P. 1908. Fossil turtles of North America.
Carnegie Institute of Washington, Publication 75:568 pp.
Head, J. J., P. A. Holroyd, J. H. Hutchison, and R. L.
Ciochon. in prep. First report of snakes (Serpentes)
from the late middle Eocene Pondaung Formation,
Myanmar.
Head, J. J., S. M. Raza, and P. D. Gingerich. 1999.
Drazinderetes tethyensis, a new large trionychid(Reptilia: Testudines) from the marine Eocene
Drazinda Formation of the Sulaiman Range, Punjab(Pakistan). Contributions from the Museum ofPaleontology, University of Michigan 30:199-214.
Holroyd, P. A. and Ciochon, R. L. 1994. Relative ages of
Eocene primate-bearing deposits of Asia. Pp. 123141. In J. G. Fleagle and R. F. Kay (eds.),
Anthropoid Origins. Plenum Press, New York.
Hutchison, J. H., and D. M. Bramble. 1981. Homologyof the plastral scales of the Kinosternidae and related turtles. Herpetologica 37:73-85.
Jiménez, E., M. A. Cuesta, and S. G. Tudanca. 1994.
Vertebrados fósiles del Eoceno de Fuentesaúco(Zamora). Studia Geologica Salamanticensia
29:7-21.
Leidy, J. 1851. [Fossil tortoises from Nebraska
Territory]. Proceedings of the Academy of Natural
Sciences, Philadelphia 5: 326-327.
Leidy, J. 1871. [Remarks on extinct turtles from
Wyoming Territory, Anosteira ornata andHybemys arenarius.] Proceedings of the
Academy of Natural Sciences, Philadelphia 1871:
102-103.
Li, Jingling. 1991. Fossil reptiles from Zhaili member,
Heti Formation, Yuanqu, Shanxi. VertebrataVol. 10, p. 51

PalAsiatica 29(3):190-203.
Linnaeus, C. 1758. Systema Naturae 10th ed., vol. 1.
Stockholm, 824 pp.
Lydekker, R. 1887. Eocene chelonians from the SaltRange. Paleontologica Indica 4:59-65.
Lydekker, R. 1889. Chapter III. Class Reptilia – continued. Orders Anomodontia, Sauropterygia, andChelonia. Pp. 1053-1118. In: H. A. Nicholson and
R. Lydekker, Manual of Paleontology. Vol 2. W.
Blackwood and Sons, Edinburgh. 3rd ed.
Müller, J., and J. Henle. 1837. Gattungen der Haifische
und Rochen nach einer von ihm mit Hrn. Henle
unternommenen gemeinschaftlichen Arbeit über die
Naturgeschichte der Knorpelfische. Bericht der
Akademie der Wissenschaften, Berlin 1:111-118.
Noulet, J. B. 1867. Nouveau genre de Tortues fossiles
sous le nom d’Allaeochelys. Mémoires de l’Académie des sciences, Toulouse (6e sér.) 5:172177.
Ramsey, E. P. 1886 [1887]. On a new genus and speciesof fresh water tortoise from the Fly River, New
Guinea. Proceedings of the Linnean Society of New
South Wales (2)1:158-162.
Rage, J.-C. 1987. Lower vertebrates from the earlymiddle Eocene Kuldana Formation of Kohat(Pakistan): Squamata. University of Michigan
Contribution from the Museum of Paleontology
27:187-193.
Sahni, A. 1984. Upper Cretaceous-early Palaeogene
palaeobiogeography of India based on terrestrial
vertebrate faunas. Mémoires de la Sociéte´géologique de France, N. S. 147: 125-137.
Savage, D. E., and D. E. Russell. 1983. Mammalian
Paleofaunas of the World. Addison-Wesley,
Reading Massachusetts. 432 pp.
Smith, M. A. 1931. The fauna of British India, including Ceylon and Burma. Reptilia and Amphibia.
Vol. 1. Loricata, Testudines. Taylor and Francis,
London. 185 pp.
Soe, Aung Naing, Myitta, Soe Thura Tun, Aye Ko Aung,
Tin Thein, B. Marandat, S. Ducrocq, & J.-J. Jaeger.
2002. Sedimentary facies of the late Middle Eocene
Pondaung Formation (central Myanmar) and theVol. 10, p. 52

Asiatic Herpetological Researchpaleoenvironments of its anthropoid primates.
Comptes Rendus Palevol 1:153-160.
Sun, A., J. Li, X. Ye, Z. Dong, L. Lou. 1992. The
Chinese fossil reptiles and their kins. Science Press,
Beijing. 242 pp.
Tsubamoto, T., N. Egi, M. Takai, N. Shigehara, Aye Ko
Aung, Tin Thein, Aung Naing Soe and Soe Thura
Tun. 2000,: A preliminary report on the Eocene
mammals of the Pondaung fauna, Myanmar. Asian
Paleoprimatology 1: 29-101.
Tsubamoto, T., Takai, M., Shigehara, N., Egi, N., Soe
Thura Tun, Aye Ko Aung, Maung Maung, Danhara,T., and Suzuki, H. 2002. Fission-track zircon age of
the Eocene Pondaung Formation, Myanmar. Journalof Human Evolution 42: 361-369.
Wood, R. C. 1983. Kenyemys williamsi, a fossil pelomedusid turtle from the Pliocene of Kenya. Pp. 74-85.
In: A. G. Rhodin et al. (eds). Advances in
Herpetology and Evolutionary Biology.
Ye (Yeh), X. 1963. Fossil turtles of China.
Palaeontologica Sinica, new Series C (18):112 pp.
Zangerl, R. 1947. A new anosteirine turtle from
Manchuria. Fieldiana, Geology 10:13-21.

2004