Genus: Yelmochelys BRINKMAN, AGUILLON-MARTINEZ, HUTCHISON, & BROWN, 2016
Etymology: Spanish, yelmo, "helment" and Greek, chelys, "turtle"; in reference to the helment-like shape of the turtle.

Species: rosarioae BRINKMAN, AGUILLON-MARTINEZ, HUTCHISON, & BROWN, 2016
Etymology: In honor of Rosario Gomez-Nunez, whose work as director of the Paleontological Commission of Coahuila has led to a gret increase in aarensis and understanding of the paleontolgoical resorurces of Coahuila.

Holotype: CPC 278

Locality: Turtle Heaven Locality, Ejido of La Parita, Coahuila State, Mexico.

Horizon: Upper non-marine beds in the Cerro del Pueblo Formation.

Biostratigraphy:

Age: Late Campanian Stage, Middle Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: A partial plastron, including the entoplastron, partial hyo- and hypoplastra, adn complete xiphiplastra.

Referred material:

CPC 279: Costal 1.

CPC 280: Costal 1.

CPC 284: Costal 6.

CPC 285: Costal 6.

CPC 286: Unidentified costal.

CPC 287: Costal 6.

CPC 288: Costal 6.

CPC 289: Costal 3.

CPC 290: Costal 6.

CPC 900: Neural 1.

CPC 291: Neural 2, conjoined neural 7 and 8.

CPC 321: Neural 2.

CPC 322: Neural 3.

CPC 323: Neural 3.

CPC 325: Neural 4.

CPC 326: Neural 6.

CPC 322: Neural 3.

CPC 323: Neural 3.

CPC 325: Neural 4.

CPC 326: Neural 6.

CPC 332: Neural 7.

CPC 337: Peripheral 1.

CPC 342: Peripheral 6.

CPC 343: Peripheral 6.

CPC 344: Conjoined peripheral 5 and 6.

CPC 347: Peripheral 9.

CPC 348: Peripheral 10.

CPC 349: Peripheral 10.

CPC 356: Peripheral 3.

CPC 358: Peripheral 7.

CPC 359: Periphearl 2.

CPC 361: Peripheral 2.

CPC 369: Periphearl 8.

CPC 370: Peripheral 8.

CPC 372: Periphearl 10.

CPC 375: C1.

CPC 379: Costal 2.

CPC 380: Costal 3.

CPC 381: Costal 3.

CPC 383: Costal 4,

CPC 384: Costal 4.

CPC 385: Costal 4.

CPC 386: Costal 4,

CPC 387: Costal 4.

CPC 391: Costal.

CPC 293: Costal.

CPC 394: Costal.

CPC 395: Pygal.

CPC 399: Hyoplastron.

CPC 400: Hyypolastron.

CPC 401: Hyoplastron.

CPC 409: Costal.

CPC 410: Costal 3.

 CPC 898: Peripherals 6-7 in articulation.

CPC 899: Peripheral 3.

Locality: NAP locality, Ejido of La Parrita, Coahuila State, Mexico.

Horizon: Upper non-marine beds in the Cerro del Pueblo Formation.

Biostratigraphy:

Age: Late Campanian Stage, Middle Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CPC 292, 293: Pygals.

CPC 327: Neural.

CPC  328: Neural 6.

CPC 329: Neural 3.

CPC 330: Neural 3.

CPC 331: Neural 6.

CPC 338: Peripheral.

CPC 353: Hypoplastron.

CPC 376: Costal 1.

Locality: Theropod locality, Ejido of La Parrita, Coahuila State, Mexico.

Horizon: Upper non-marine beds in the Cerro del Pueblo Formation.

Biostratigraphy:

Age: Late Campanian Stage, Middle Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CPC 282: Costal 3-4.

CPC 333: Neural 3.

CPC 334: Neural 5.

CPC 335: Neural 5.

CPC 336: Neural 4.

CPC 346: Peripheal 8.

CPC 377: Costal 1.

CPC 388: Costal 5.

CPC 402: Hyoplastron.

CPC 411: Costal 3.

CPC 412: Costal 4.

Locality: Unknown, Coahuila State, Mexico.

Horizon: Upper non-marine beds in the Cerro del Pueblo Formation.

Biostratigraphy:

Age: Late Campanian Stage, Middle Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CPC 283: Costal 5.

Locality: Las Aguilas locality, Ejido of Porvenir de Jalpa, Coahuila State, Mexico.

Horizon: Upper non-marine beds in the Cerro del Pueblo Formation.

Biostratigraphy:

Age: Late Campanian Stage, Middle Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CPC 897: Nuchal.

Locality: El Pelillal Locality, Coahuila State, Mexico.

Horizon: Canon del Tule Formation.

Biostratigraphy:

Age: Late Campanian Stage, Middle Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CPC 281: Costal 2.

CPC 282: Costal 2.

CPC 340: Peripheral 6.

CPC 341: Peripheral 5.

CPC 360: Peripheral 2.

CPC 355: Peripheral 3.

CPC 362: Peripheral 4.

CPC 363: Peripheral 4.

CPC 364: Periphearl 4.

CPC 366: Peripheral 6.

CPC 371: Peripheral 9.

COC 378: Costal 2.

CPC 397: Hyoplastron.

CPC 398: Hyoplastron.

CPC 403: Costal 3.

CPC 403: Costal 3.

CPC 404: Costal 3.

CPC 405: Costal 3.

CPC 406; Costal 3.

CPC 407-408: Costal 3.

CPC 413: Peripheral 10.