Neochelys

Neochelys Temporal range: Early to Late Eocene [1] PreꞒ Ꞓ O S D C P T J K Pg N
N. franzeni specimens at the Senckenberg Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Pleurodira
Family:	Podocnemididae
Subfamily:	Erymnochelyinae
Genus:	† Neochelys Bergounioux, 1954
Type species
† Emys capellinii de Zigno, 1890
Species
See text

Neochelys (Greek for "new turtle") is an extinct genus of freshwater side-necked turtle that inhabited Europe during the Eocene. It was a diverse genus known throughout western and southern Europe from the Ypresian to the Priabonian. ^[1]

Taxonomy

The following species are known: ^{[1] [2]}

• †N. arenarumde Broin, 1977 – early-mid Ypresian of France (Lignites de Soissonais) ^[3]
• †N. capellinii(de Zigno, 1890) (type species) – latest Ypresian or earliest Lutetian of Italy (Monte Bolca) (= Emys capellinii)
• †N. eocaenica(de Stefano, 1902) – latest Ypresian or earliest Lutetian of France (Grès d'Aigne Formation)
• †N. franzeniSchleich, 1993 – early Lutetian of Germany (Messel Formation) ^[4]
• †N. laurentiTong, 1998 – mid-late Ypresian of France (Saint-Papoul Formation) ^[5]
• †N. liriaePérez-García & de Broin, 2013 – mid-late Ypresian of France (Grès d'Assignan Formation)
• †N. salmanticensisJimenez, 1971 – Bartonian of Spain (=Podocnemis carbajosai) ^[6]
• †N. zamorensisJimenez-Fuentes, 1992 – late Lutetian of Spain (Entrala Formation)

Well-preserved specimens of N. franzeni are known from the Messel Formation

Indeterminate remains are known from the latest Eocene (Priabonian) of France and Spain; these have not been assigned to a specific species, but represent the youngest record of the genus. ^[1] The species "N." fajumensis from the Oligocene of Egypt was briefly assigned to this genus, but is now thought to belong to its own genus, Shetwemys . ^[7]

Morphological analyses suggest that Neochelys likely represents an ancient lineage of the Erymnochelyinae, sister to the clade composed of the South American Peltocephalus and the Malagasy Erymnochelys . ^[4] The taxonomic relationships between the multiple Neochelys species remain largely unknown. It has been suggested that N. eocaenica, N. capellinii, and N. salmanticensis together form a species complex known as the "N. eocaenica complex", but this is uncertain. ^[1]

Palaeopathology

A Neochelys sp. specimen exhibiting pelvic asymmetry has been found in the Duero Basin. Potential causes, none of which can be ruled out, of this palaeopathology include metabolic bone disease, a developmental abnormality, or some sort of traumatic injury. ^[8]

Ecology

A pathological Neochelys shell is known from the middle Eocene of Spain, hosting abnormalities that were previously thought to be the result of a crocodile attack. However, more recent studies instead suggest that these may instead occurred from parasites or a bacterial/fungal infection. ^[9]

References

1. Pérez-García, Adán; de Lapparent de Broin, France (1 June 2013). "A new species of Neochelys (Chelonii, Podocnemididae) from the Ypresian (Early Eocene) of the South of France" . Comptes Rendus Palevol. 12 (5): 269–277. Bibcode:2013CRPal..12..269P. doi:10.1016/j.crpv.2013.05.011.
2. "PBDB Taxon". paleobiodb.org. Retrieved 2024-10-21.
3. Martín-Jiménez, Marcos; Pérez-García, Adán (28 March 2023). "Neuroanatomical study of the podocnemidid turtle Neochelys arenarum (Pleurodira), from the early Eocene of France". The Anatomical Record . 308 (6): 1646–1658. doi: 10.1002/ar.25217 . ISSN   1932-8486. PMC   12062562 . PMID   36974769.
4. Cadena, Edwin (27 August 2015). "A global phylogeny of Pelomedusoides turtles with new material of Neochelys franzeni Schleich, 1993 (Testudines, Podocnemididae) from the middle Eocene, Messel Pit, of Germany". PeerJ . 3 e1221. doi: 10.7717/peerj.1221 . ISSN   2167-8359. PMC   4556147 . PMID   26336649.
5. Pérez-García, Adán; de Lapparent de Broin, France (1 December 2015). "New insights into the anatomy and systematic of 'Papoulemys' laurenti, a representative of Neochelys (Chelonii, Podocnemididae) from the early Eocene of the south of France" . Paläontologische Zeitschrift . 89 (4): 901–923. Bibcode:2015PalZ...89..901P. doi:10.1007/s12542-015-0259-3.
6. Pérez-García, Adán; Guerrero, Andrea; Martín de Jesús, Santiago; Ortega, Francisco (18 April 2023). "Shell characterization of the youngest valid species of the European Eocene genus Neochelys (Pleurodira, Podocnemididae): The Spanish Bartonian Neochelys salmanticensis". The Anatomical Record . 308 (6): 1553–1572. doi: 10.1002/ar.25225 . ISSN   1932-8486. PMC   12062568 . PMID   37072560.
7. Gaffney, Eugene S.; Meylan, Peter Andre; Wood, Roger Conant; Simons, Elwyn L.; Campos, Diógenes de Almeida (2011). "Evolution of the side-necked turtles: the family Podocnemididae". Bulletin of the American Museum of Natural History . 350: 1–237. doi:10.1206/350.1. hdl:2246/6110.
8. Guerrero, Andrea; Ortega, Francisco; Martín de Jesús, Santiago; Pérez‐García, Adán (12 April 2024). "Postcranial anomalies of Eocene freshwater pleurodiran and cryptodiran turtles from the Spanish Duero Basin". The Anatomical Record . 308 (6): 1659–1676. doi:10.1002/ar.25443. ISSN   1932-8486. PMC   12062566 . PMID   38613176 . Retrieved 16 September 2025– via Wiley Online Library.
9. Guerrero, Andrea; Ortega, Francisco; Martín de Jesús, Santiago; Pérez-García, Adán (March 2023). "Analysis of the anomalies in a Middle Eocene shell of Neochelys (Pleurodira, Podocnemididae) from the Duero Basin (Zamora, Spain)". Diversity . 15 (3): 314. Bibcode:2023Diver..15..314G. doi: 10.3390/d15030314 .