Astrochelys rogerbouri

Extinct species of tortoise

Astrochelys rogerbouri
Temporal range: Holocene
PreꞒ
O
S
D
C
P
T
J
K
Pg
N
Conservation status
Extinct (before 954 AD)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Suborder: Cryptodira
Superfamily: Testudinoidea
Family: Testudinidae
Genus: Astrochelys
Species:
A. rogerbouri
Binomial name
Astrochelys rogerbouri
Kehlmaier et. al., 2023

Astrochelys rogerbouri is an extinct tortoise species in the family Testudinidae which formerly lived in Madagascar.

Discovery and naming

The type specimen, MNHN.F.MAD480, is a nearly complete tibia and was collected in June 1900 in Ambolisatra, Madagascar by Guillaume Grandidier. It is kept at the Muséum national d’histoire naturelle. This material was originally assigned as a juvenile specimen of Aldabrachelys abrupta, likely as the two share a type locality, and it was only found to represent a new species after DNA analysis.[1][2]

The specific name honors Roger Bour, a herpetologist and expert on western Indian Ocean giant tortoises who helped in the investigation describing this species.[1]

Description

Astrochelys rogerbouri was a large tortoise species, with an estimated straight carapace length of 50 cm. This matches the size of its congeneric relative, the angonoka tortoise, which has a maximum straight carapace length of 51.9 cm. Though it is only known from a tibia, its mitochondrial genome shows deep genetic divergence, supporting its status as a distinct species.[1]

Ecology

In Ambolisatra, the presence of both A. rogerbouri and Aldabrachelys abrupta have been confirmed through genomic analysis of remains found at the site, confirming that the two species occurred in microsympatry. Additional remains from Ambolisatra have been morphologically referred to Aldabrachelys grandidieri and the extant radiated tortoise (Astrochelys radiata), but these records have not been genetically verified. The subfossil bones found in Ambolisatra assigned to Astrochelys radiata (as well as 3 other subfossil records of A. radiata and Astrochelys sp. outside the current range of the species) may represent Astrochelys rogerbouri. Though the remains identified as Aldabrachelys grandidieri from Ambolisatra are fragmentary and their assignment is questionable, Ambolisatra is geographically within the range of genetically-confirmed Aldabrachelys grandidieri records, and the species may indeed have coexisted with Astrochelys rogerbouri there. Ambolisatra is also near the northwestern limit of the radiated tortoise's current range, and within the range of the extant spider tortoise (Pyxis arachnoides). In total, 5 tortoise species undoubtedly formerly lived in southwestern Madagascar (the spider tortoise, the two extinct Aldabrachelys species, the radiated tortoise and Astrochelys rogerbouri), an exceptional level of sympatric tortoise diversity.[1]

Judging from the former sympatry of A. rogerbouri and the radiated tortoise, the two may have had different preferences in diet or habitat, and the angonoka tortoise may be hypothesized to have shared such preferences with A. rogerbouri.[1]

Extinction

It is unknown when A. rogerbouri became extinct, though it is believed to have survived until 1262 to 1069 years B.P. (between 761 to 954 AD) at least.[1]

References

  1. ^ a b c d e f Kehlmaier, Christian; Graciá, Eva; Ali, Jason R.; Campbell, Patrick D.; Chapman, Sandra D.; Deepak, V.; Ihlow, Flora; Jalil, Nour-Eddine; Pierre-Huyet, Laure; Samonds, Karen E.; Vences, Miguel; Fritz, Uwe (2023-01-13). "Ancient DNA elucidates the lost world of western Indian Ocean giant tortoises and reveals a new extinct species from Madagascar". Science Advances. 9 (2): eabq2574. doi:10.1126/sciadv.abq2574. ISSN 2375-2548. PMC 9833658. PMID 36630487.
  2. ^ "New species of large tortoise discovered after a century of mistaken identity". www.nhm.ac.uk. Retrieved 2023-02-12.

External links

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Tortoise family
Genera
Species of the tortoise family
AgrionemysAldabrachelysAstrochelys
CentrochelysChelonoidis
Galápagos tortoise
Chelonoidis complex
†Cheirogaster
  • †Cheirogaster bacharidisi
  • †Cheirogaster gymnesica
  • †Cheirogaster schafferi
ChersinaChersobiusCylindraspisGeocheloneGopherus†Hadrianus
  • †Hadrianus corsoni
  • †Hadrianus majusculus
  • †Hadrianus octonaria
  • †Hadrianus robustus
  • †Hadrianus schucherti
  • †Hadrianus utahensis
  • †Hadrianus vialovi
HesperotestudoHomopusIndotestudoKinixysMalacochersusManouriaMegalochelysPsammobatesPyxisStigmochelysStylemys
  • †Stylemys botti
  • †Stylemys calaverensis
  • †Stylemys canetotiana
  • †Stylemys capax
  • †Stylemys conspecta
  • †Stylemys copei
  • †Stylemys emiliae
  • †Stylemys frizaciana
  • †Stylemys karakolensis
  • †Stylemys nebrascensis
  • †Stylemys neglectus
  • †Stylemys oregonensis
  • †Stylemys pygmea
  • †Stylemys uintensis
  • †Stylemys undabuna
Testudo
Phylogenetic arrangement of turtles based on turtles of the world 2017 update: Annotated checklist and atlas of taxonomy, synonymy, distribution, and conservation status. Key: †=extinct.
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Suborder
Superfamily
Family
Cryptodira
Chelonioidea
(Sea turtles)
Cheloniidae
Dermochelyidae
 
Kinosternoidea
Dermatemydidae
Kinosternidae
Testudinoidea
Emydidae
Geoemydidae
 Platysternidae
Testudinidae
Trionychia
Carettochelyidae
Trionychidae
 
 
Chelydridae
Nanhsiungchelyidae
Protostegidae
 
Pleurodira
 
Araripemydidae
Bothremydidae
Chelidae
Pelomedusidae
Podocnemididae
Sahonachelyidae
 
 
 
  • Phylogenetic arrangement of turtles based on Turtles of the World 2017 Update: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status. † = extinct.