Black spine-neck swamp turtle

{{Short description|Species of turtle}}

{{Speciesbox

| image = Acanthochelys spixii.jpg

| status = LR/nt

| status_system = IUCN2.3

| status_ref = {{Cite iucn|author=Tortoise & Freshwater Turtle Specialist Group|title=Acanthochelys spixii|year=1996|errata=2016 |page=e.T76A97260200|doi=10.2305/IUCN.UK.1996.RLTS.T76A13075785.en|access-date=11 January 2018}}

| genus = Acanthochelys

| species = spixii

| authority = (A.M.C. Duméril & Bibron, 1835)Duméril AMC, Bibron G (1835). Erpétologie Générale ou Histoire Naturelle Complète des Reptiles, Tome Second [Volume 2]. Paris: Librairie Encyclopédique de Roret. ii + 680 pp. (Platemys spixii, new name, p. 409). (in French).

| synonyms =

• Emys depressa
  {{small|Spix, 1824: 4
  (junior homonym)}}Spix JB von (1824). Animalia nova; sive, Species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis 1817-20 collegit et descripsit. Munich: F.S. Hübschmann. iv + 53 pp. (Emys depressa, new species, p. 4). (in Latin).
• Emys aspera
  {{small|Gray, 1830: 16 (10:7)
  (nomen dubium et oblitum)}}
• Platemys spixii
  {{small|A.M.C. Duméril & Bibron, 1835: 409}}
  {{small|(nomen novum)}}
• Acanthochelys spixii
  {{small|— Gray, 1873: 305
  (recombination)}}Gray JE (1873). "Observations on Chelonians, with Descriptions of new Genera and Species". Annals and Magazine of Natural History, Fourth Series 11: 289-308. (Acanthochelys spixii, new combination, p. 305).

| synonyms_ref = Turtle Taxonomy Working Group (van Dijk PP, Iverson JB, Rhodin AGJ, Shaffer HB, Bour R) (2014). "Turtles of the world, 7th edition: annotated checklist of taxonomy, synonymy, distribution with maps, and conservation status". In: Rhodin AGJ, Pritchard PCH, van Dijk PP, Saumure RA, Buhlmann KA, Iverson JB, Mittermeier RA (Editors) (2014) Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs 5 (7): 000.329–000.479, doi:10.3854/ crm.5.000.checklist.v7.2014.

}}

The black spine-neck swamp turtle (Acanthochelys spixii), also commonly known as the spiny-neck turtle or Spix's sideneck turtle, is a species of turtle in the family Chelidae. The species is endemic to South America, specially in the Southern Cone region.