A taxonomic revision of geoemydid turtles from Siwalik-age of India and Pakistan
Author
Garbin, Rafaella C.
A8FCEF2B-7524-46C3-808C-D9CBFBC08017
Department of Geosciences, University of Fribourg, Fribourg; Chemin du Musée 6, 1700 Fribourg, Switzerland.
garbin.rafaella@gmail.com
Author
Bandyopadhyay, Saswati
02005D35-6DA9-4A7E-B838-16F4FEF108DA
Geological Studies Unit, Indian Statistical Institute, Kolkata; Barrackpore Trunk Road 233, Kolkata, India.
saswati@isical.ac.in
Author
Joyce, Walter G.
C30D317A-0029-439C-8446-31281771ADA5
Department of Geosciences, University of Fribourg, Fribourg; Chemin du Musée 6, 1700 Fribourg, Switzerland.
walter.joyce@unifr.ch
text
European Journal of Taxonomy
2020
2020-05-26
652
1
67
journal article
10.5852/ejt.2020.652
64fd24bb-ee1d-44d7-ac6a-25e8d5f96777
2118-9773
3860236
DC65C142-53F1-4416-A916-8F78C27DCF93
Hardella thurjii
(Gray, 1831)
Figs 19–21
Emys thurjii
Gray, 1831a: 22
(
nomen novum
).
Emys thuryi
Gray, 1831c: 8
(
nomen oblitum
).
Emys thuji
Gray, 1831b
(ex errore): pl. 73
.
Emys flavonigra
Lesson, 1831: 120
.
Emys thugi
Gray, 1832
(ex errore): Directions
.
Clemmys (Clemmys) thurgii
Fitzinger, 1835: 123
(
nomen novum
).
Kachuga oldhami
Gray, 1869: 200
.
Batagur falconeri
Lydekker, 1885a: 187
Clemmys watsoni
Lydekker, 1886a: 541
Hardella indi
Gray, 1870: 58
.
Geoemyda pilgrimi
Prasad & Satsangi, 1967
.
Emys thurgii
–
Gray 1844: 17
.
Emys thurgi
–
Gray 1856
(“1855”): 21
.
Clemmys thurgii
–
Strauch 1862: 32
.
Batagur thurgii
–
Theobald 1868: 12
.
Hardella thurgi
–
Gray 1870: 58
.
Batagur (Hardella) thurgi
–
Anderson 1879: 764
.
Hardella thurjii
–
Siebenrock 1909: 456
.
Hardella thurgi
–
Smith 1931: 50
.
Hardella thurjii thurjii
–
Wermuth & Mertens 1977: 40
.
Hardella thurjii indi
–
Wermuth & Mertens 1977: 40
.
Hardella thurji
–
Pritchard 1979
(ex errore): 193
.
Hardella thurji thurji
–
Obst 1985: 221
.
Type
Unknown (
Iverson 1992
).
Material examined
INDIA
•
1 specimen
, holotype of
Batagur falconeri
;
Siwalik Hills
; Miocene–Pliocene;
BMNH 39835
•
1 specimen
;
Siwalik Hills
; Miocene–Pliocene;
BMNH R.890
•
1 specimen
, holotype of
Clemmys watsoni
;
Gulf of Cambay
,
Gujarat
,
Piram Island
; Late Miocene–Pliocene;
BMNH R.748
.
Type
locality
“
India
” (
Iverson 1992
).
Occurrence
Miocene/Pliocene – Recent.
Differential osteological diagnosis using shell characters
Hardella thurjii
can be differentiated from other geoemydids by large carapace size (up to
60 cm
in females), presence of hexagonal, nearly square second to fourth vertebrals, a first vertebral scute that is wider posteriorly, presence of an inflection at the margin of the gulohumeral sulcus, and an entoplastron that is not intersected by the humeropectoral sulcus.
Description of material examined
BMNH 39835 (
Fig. 19
),
holotype
of
Batagur falconeri
– This is an almost complete shell, exceptionally well preserved, from the Miocene/Pliocene of the Siwalik Hills, likely of
India
, originally figured and described in three views by
Lydekker (1885a
: pls 23.1, 24.4). Our figures are overall comparable to those of Lydekker, although we see more details to the peripherals (
Fig. 19
). The specimen clearly represents an adult female specimen based on overall size (carapace length greater than
40 cm
). A small keel is present on neurals IV and VI. There are no signs of growth annuli. All neural bones have short anterior sides. The third neural is half one and a half time longer than the other neural bones. The cervical scute is present, longer than wide. The first vertebral scute is broader posteriorly and narrows anteriorly. The second and third vertebrals are much broader than the other vertebral scutes. The fifth vertebral has an anterolateral constriction. Marginal scutes IV–X overlap the adjacent costal bones. The anterior and posterior plastral margins are not preserved. The pectoroabdominal sulcus has lateral notches, suggesting the former presence of longitudinal keels as a juvenile. The pectoroabdominal sulcus does not intersect the hyo-hypoplastron suture and contacts the fifth marginal scute. Axillary and inguinal scutes are likely present.
BMNH R.748 (
Fig. 20
),
holotype
of
Clemmys watsoni
– This specimen originates from the Late Miocene–Pliocene of Piram Island, Gulf of
Cambay
,
Gujarat
,
India
, was presented to the BMNH in 1886 by Col. J.W. Watson and figured and described in a small contribution from
Lydekker (1886a
: pl. 1). Our illustrations in three views overall confirm most of Lydekker’s observations, but we see fewer details along the neural column and the damaged portions of the costals and peripherals. The specimen is almost complete, full size, and misses some lateral peripheral bones (right and left), the anterior plastral margin, the posterior plastral lobe, and the right bridge (
Fig. 20
). The specimen is likely an adult considering its size (carapace length greater than
15 cm
) and perhaps a male specimen, as modern male individuals of
H. thurjii
reach up to
18 cm
and lack intercostal fontanelles (
Das & Bhupathy 2009a
). Most sulci and sutures of the carapace are visible, as well as a knob on neurals IV and VIII, indicating the presence of a median keel. Growth annuli are present. The cervical scute is as wide as long and lacks a posterior notch. The first vertebral scute is wider than long, its lateral sides converge anteriorly and lack an anterolateral constriction, and it contacts the first marginal scute. The neural bones are hexagonal and anteriorly short-sided. The third vertebral has straight lateral sides and the posterior margin has an anteriorly oriented inflection that crosses the suture between neural bones III–IV. The fifth vertebral scute has an anterolateral constriction. The pygal bone is completely intersected by the twelfth intermarginal sulcus. The humeropectoral sulcus is located posterior to the entoplastron. The pectoral scute contacts the fifth marginal. For a more extensive description of this specimen, we refer to
Lydekker (1886a)
.
BMNH R.890 (
Fig. 21
) – This specimen is from the Miocene/Pliocene of the Siwalik Hills, likely of
India
, was purchased by P.T. Cautley in 1840, but remained unfigured to date. It is a crushed, partial specimen, that probably represents an adult female considering its large size (carapace length greater than
20 cm
). Both the anterior and posterior margins of the carapace are missing. Neural bones III and IV have a knob, indicating the presence of a median carapacial keel. Neural bones II–IV are hexagonal with anterior short sides. The first vertebral scute has anteriorly converging lateral sides. The third vertebral scute has straight lateral sulci. The posterior margins of the first and second pleurals are straight, placed over costals II and IV, respectively, and lack an anterior projection. Both the anterior and posterior plastral margins are not preserved. The plastron has two lateral longitudinal keels, which cross the lateral sides of the hyo- and hyoplastra. The humeropectoral sulcus is apparently located posterior to the entoplastron, which is not preserved. Inguinal scutes are likely present that contact the femoral scute.
Fig. 19.
BMNH 39835, holotype of
Batagur falconeri
Lydekker, 1885
, here identified as a synonym of
Hardella thurjii
(Gray, 1831)
.
A
. Photograph of carapace.
B
. Illustration of carapace.
C
. Photograph of plastron.
D
. Illustration of plastron. Scale bar: 3 cm.
Fig. 20.
BMNH R.748, holotype of
Clemmys watsoni
Lydekker, 1886a
, here identified as synonym of
Hardella thurjii
(Gray, 1831)
.
A
. Photograph of carapace.
B
. Illustration of carapace.
C
. Photograph of carapace in lateral view.
D
. Illustration of carapace in lateral view.
E
. Photograph of plastron.
F
. Illustration of plastron. Scale bar: 3 cm.
Fig. 21.
BMNH R.890, referred to
Hardella thurgi
(Gray, 1831)
by
Lydekker (1889b)
, here identified as
Hardella thurjii
(Gray, 1831)
.
A
. Photograph of carapace.
B
. Illustration of carapace.
C
. Photograph of plastron.
D
. Illustration of plastron. Scale bar: 3 cm.
Comments
We here attribute these specimens to
Hardella thurjii
based on the presence of a short median keel, large and square second and third vertebrals that are about the same width as the fourth vertebral scute, large inguinal scute, and an entoplastron that is not intersected by the humeropectoral sulcus. This confirms the synonymy of
B. falconeri
and
C. watsoni
with
H. thurjii
, as first suggested by
Boulenger (1889)
and later supported by
Lydekker (1889a)
, TEWG (2015) and TTWG (2017). We furthermore follow
Das (1994)
by recognizing the synonymy of
Geoemyda pilgrimi
with
H. thurjii
(followed by TEWG 2015 and TTWG 2017) although we did not study the
holotype
of this species firsthand.