taxonID	type	format	identifier	references	title	description	created	creator	contributor	publisher	audience	source	license	rightsHolder	datasetID
276487C6273BFF91C9759D94FD907EB8.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608719/files/figure.png	https://doi.org/10.5281/zenodo.15608719	FIG. 2. — Cranium and right mandible of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MNHN.F.PRU11 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in dorsal (A), right lateral (B), left lateral (C), and ventral (D) view. The mandible is shifted slightly anteriorly relative to the mandibular fossa on the cranium, which gives the wrong impression of some degree of underbite. Scale bar: 200 mm. Photos by Philippe Loubry and Lilian Cazes.	FIG. 2. — Cranium and right mandible of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MNHN.F.PRU11 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in dorsal (A), right lateral (B), left lateral (C), and ventral (D) view. The mandible is shifted slightly anteriorly relative to the mandibular fossa on the cranium, which gives the wrong impression of some degree of underbite. Scale bar: 200 mm. Photos by Philippe Loubry and Lilian Cazes.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C6273BFF91C9759D94FD907EB8.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608721/files/figure.png	https://doi.org/10.5281/zenodo.15608721	FIG. 3. — Cranium and atlas of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal view (A) with corresponding line drawing, detail of the vertex of the cranium in dorsal view (B) with corresponding line drawing, and left lateral view (C). Hatching for main break surfaces; dashed lines on line drawing for more tentative interpretations of sutures and edges; dashed lines on photo for maxilla-premaxilla suture. Scale bar: 200 mm. Photos by Olivier Lambert.	FIG. 3. — Cranium and atlas of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal view (A) with corresponding line drawing, detail of the vertex of the cranium in dorsal view (B) with corresponding line drawing, and left lateral view (C). Hatching for main break surfaces; dashed lines on line drawing for more tentative interpretations of sutures and edges; dashed lines on photo for maxilla-premaxilla suture. Scale bar: 200 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C6273BFF91C9759D94FD907EB8.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608723/files/figure.png	https://doi.org/10.5281/zenodo.15608723	FIG. 4. — Partial left mandible of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MNHN.F.PRU11 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in lateral (A), dorsal (B), and medial (C) view. Scale bar: 200 mm. Photos by Olivier Lambert.	FIG. 4. — Partial left mandible of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MNHN.F.PRU11 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in lateral (A), dorsal (B), and medial (C) view. Scale bar: 200 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C6273BFF91C9759D94FD907EB8.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608717/files/figure.png	https://doi.org/10.5281/zenodo.15608717	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C6273BFF91C9759D94FD907EB8.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608769/files/figure.png	https://doi.org/10.5281/zenodo.15608769	APPENDIX 1. — Textured 3D model of the cranium of Chilcacetus cavirhinus MUSM 4692, available at: https://doi.org/10.7934/P5641	APPENDIX 1. — Textured 3D model of the cranium of Chilcacetus cavirhinus MUSM 4692, available at: https://doi.org/10.7934/P5641	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608725/files/figure.png	https://doi.org/10.5281/zenodo.15608725	FIG. 5. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in dorsal view with corresponding line drawing. Hatching for main break surfaces; dashed lines for incomplete parts. Scale bar: 200 mm. Photos by Olivier Lambert.	FIG. 5. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in dorsal view with corresponding line drawing. Hatching for main break surfaces; dashed lines for incomplete parts. Scale bar: 200 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608727/files/figure.png	https://doi.org/10.5281/zenodo.15608727	FIG. 6. — Cranium of Chilcacetus ullujayensis n. sp.MUSM 2527 (holotype,Chilcatay Formation,East Pisco Basin,Peru) in left lateral view (A), detail of the neurocranium in right (B) and left (C) lateral view.Dashed lines for main sutures and some bone outlines.Scale bars: A,200 mm; B, C, 100 mm.Photos by Olivier Lambert.	FIG. 6. — Cranium of Chilcacetus ullujayensis n. sp.MUSM 2527 (holotype,Chilcatay Formation,East Pisco Basin,Peru) in left lateral view (A), detail of the neurocranium in right (B) and left (C) lateral view.Dashed lines for main sutures and some bone outlines.Scale bars: A,200 mm; B, C, 100 mm.Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608729/files/figure.png	https://doi.org/10.5281/zenodo.15608729	FIG. 7. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in ventral view with corresponding line drawing. Hatching for main break surfaces; dashed lines for reconstructed parts and tentative outline of the posterior process of the left periotic. Scale bar: 200 mm. Photos by Olivier Lambert.	FIG. 7. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in ventral view with corresponding line drawing. Hatching for main break surfaces; dashed lines for reconstructed parts and tentative outline of the posterior process of the left periotic. Scale bar: 200 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608731/files/figure.png	https://doi.org/10.5281/zenodo.15608731	FIG. 8. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru). Detail of the left side of the neurocranium in ventrolateral view with corresponding line drawing. Dashed line for tentative outline of the posterior process of the left periotic. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 8. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru). Detail of the left side of the neurocranium in ventrolateral view with corresponding line drawing. Dashed line for tentative outline of the posterior process of the left periotic. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608733/files/figure.png	https://doi.org/10.5281/zenodo.15608733	FIG. 9. — In situ left periotic of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation,East Pisco Basin,Peru) in ventral view with corresponding line drawing. Dashed line for tentative outline of the posterior process of the left periotic. Scale bar: 20 mm. Photos by Olivier Lambert.	FIG. 9. — In situ left periotic of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation,East Pisco Basin,Peru) in ventral view with corresponding line drawing. Dashed line for tentative outline of the posterior process of the left periotic. Scale bar: 20 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608735/files/figure.png	https://doi.org/10.5281/zenodo.15608735	FIG. 10. — Left tympanic and left malleus of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru). Tympanic in ventral (A), dorsal (B), medial (C), lateral (D), and posterior (E) view; malleus in posteromedial view (F) and corresponding line drawing. Scale bars: A-E, 20 mm; F, 0.5 mm. Photos by Olivier Lambert.	FIG. 10. — Left tympanic and left malleus of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru). Tympanic in ventral (A), dorsal (B), medial (C), lateral (D), and posterior (E) view; malleus in posteromedial view (F) and corresponding line drawing. Scale bars: A-E, 20 mm; F, 0.5 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608737/files/figure.png	https://doi.org/10.5281/zenodo.15608737	FIG. 11. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in posterior (A) and anterodorsal (B) view. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 11. — Cranium of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in posterior (A) and anterodorsal (B) view. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608739/files/figure.png	https://doi.org/10.5281/zenodo.15608739	FIG. 12. — Partial mandibles of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in dorsal view (A); partial left mandible in lateral (B) and medial (C) view; partial right mandible in lateral view (D). Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 12. — Partial mandibles of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in dorsal view (A); partial left mandible in lateral (B) and medial (C) view; partial right mandible in lateral view (D). Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608741/files/figure.png	https://doi.org/10.5281/zenodo.15608741	FIG. 13. — Three detached teeth of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin,Peru),the two first still partly embedded in sediment. Scale bar: 20 mm. Photos by Olivier Lambert.	FIG. 13. — Three detached teeth of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin,Peru),the two first still partly embedded in sediment. Scale bar: 20 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608743/files/figure.png	https://doi.org/10.5281/zenodo.15608743	FIG. 14. — Left humerus of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in lateral (A), anterior (B), medial (C), and posterior (D) view. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 14. — Left humerus of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype, Chilcatay Formation, East Pisco Basin, Peru) in lateral (A), anterior (B), medial (C), and posterior (D) view. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608745/files/figure.png	https://doi.org/10.5281/zenodo.15608745	FIG. 15. — Three thoracic vertebrae of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype,Chilcatay Formation,East Pisco Basin,Peru). Ta in anterior (A) and left lateral (D) view; Tb in posterior (B) and right lateral (E) view; and Tc in anterior (C) and left lateral (F) view.Scale bar:50 mm.Photos by Olivier Lambert.	FIG. 15. — Three thoracic vertebrae of Chilcacetus ullujayensis n. sp. MUSM 2527 (holotype,Chilcatay Formation,East Pisco Basin,Peru). Ta in anterior (A) and left lateral (D) view; Tb in posterior (B) and right lateral (E) view; and Tc in anterior (C) and left lateral (F) view.Scale bar:50 mm.Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608717/files/figure.png	https://doi.org/10.5281/zenodo.15608717	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62736FF8EC91F9BBEFD6C7BBA.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608771/files/figure.png	https://doi.org/10.5281/zenodo.15608771	APPENDIX 2. — Textured 3D model of the cranium of Chilcacetus ullujayensis n. sp. MUSM 2527, available at: https://doi.org/10.7934/P5641	APPENDIX 2. — Textured 3D model of the cranium of Chilcacetus ullujayensis n. sp. MUSM 2527, available at: https://doi.org/10.7934/P5641	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608747/files/figure.png	https://doi.org/10.5281/zenodo.15608747	FIG. 16. — Partial cranium of Amphidelphis bakersfieldensis n. comb. MUSM 4691 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal view (A) with corresponding line drawing, in ventral view (B), and in right lateral view (C). Hatching for main break surfaces; dashed lines on photo for maxilla-premaxilla suture. Scale bar: 200 mm. Photos by Olivier Lambert.	FIG. 16. — Partial cranium of Amphidelphis bakersfieldensis n. comb. MUSM 4691 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal view (A) with corresponding line drawing, in ventral view (B), and in right lateral view (C). Hatching for main break surfaces; dashed lines on photo for maxilla-premaxilla suture. Scale bar: 200 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608749/files/figure.png	https://doi.org/10.5281/zenodo.15608749	FIG. 17. — Partial cranium of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States) in dorsal (A), ventral (B), and right lateral (C) view. Scale bar: 100 mm. Credits: Photos by Advait Jukar. Photos by Olivier Lambert.	FIG. 17. — Partial cranium of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States) in dorsal (A), ventral (B), and right lateral (C) view. Scale bar: 100 mm. Credits: Photos by Advait Jukar. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608751/files/figure.png	https://doi.org/10.5281/zenodo.15608751	FIG. 18. — Detached left part of the basicranium of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States) in lateral (A), ventral (B), and posterior (C) view. Scale bar: 50 mm. Credits: Photos by Advait Jukar. Photos by Olivier Lambert.	FIG. 18. — Detached left part of the basicranium of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States) in lateral (A), ventral (B), and posterior (C) view. Scale bar: 50 mm. Credits: Photos by Advait Jukar. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608753/files/figure.png	https://doi.org/10.5281/zenodo.15608753	FIG. 19. — Partial right mandible of Amphidelphis bakersfieldensis n. comb. MUSM 4691 (Chilcatay Formation, East Pisco Basin, Peru) in lateral (A), dorsal (B), and medial (C) view. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 19. — Partial right mandible of Amphidelphis bakersfieldensis n. comb. MUSM 4691 (Chilcatay Formation, East Pisco Basin, Peru) in lateral (A), dorsal (B), and medial (C) view. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608755/files/figure.png	https://doi.org/10.5281/zenodo.15608755	FIG. 20. — Left humerus and two cervical vertebrae of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States). Humerus in lateral (A), anterior (B), medial (C), and posterior (D) view;?4th cervical in posterior view (E); 6th cervical in posterior view (F). Scale bar: 50 mm. Credits: Photos by Advait Jukar.	FIG. 20. — Left humerus and two cervical vertebrae of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States). Humerus in lateral (A), anterior (B), medial (C), and posterior (D) view;?4th cervical in posterior view (E); 6th cervical in posterior view (F). Scale bar: 50 mm. Credits: Photos by Advait Jukar.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608717/files/figure.png	https://doi.org/10.5281/zenodo.15608717	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62729FF80C8CB98D9FB397E99.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608777/files/figure.png	https://doi.org/10.5281/zenodo.15608777	APPENDIX 4. — Textured 3D model of the cranium of Amphidelphis bakersfieldensis n. comb. MUSM 4691, available at: https://doi.org/10.7934/P5641	APPENDIX 4. — Textured 3D model of the cranium of Amphidelphis bakersfieldensis n. comb. MUSM 4691, available at: https://doi.org/10.7934/P5641	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608757/files/figure.png	https://doi.org/10.5281/zenodo.15608757	FIG. 21. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal view with corresponding line drawing and detail view of the vertex in dorsal view. Hatching for main break surfaces. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 21. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal view with corresponding line drawing and detail view of the vertex in dorsal view. Hatching for main break surfaces. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608759/files/figure.png	https://doi.org/10.5281/zenodo.15608759	FIG. 22. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin,Peru) in left (A) and right (B) lateral view. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 22. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin,Peru) in left (A) and right (B) lateral view. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608761/files/figure.png	https://doi.org/10.5281/zenodo.15608761	FIG. 23. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin, Peru) in ventral view (A) with corresponding line drawing and detail view of the right half of the basicranium in ventral view (B). Hatching for main break surfaces. Scale bars: A, 100 mm; B, 50 mm. Photos by Olivier Lambert.	FIG. 23. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin, Peru) in ventral view (A) with corresponding line drawing and detail view of the right half of the basicranium in ventral view (B). Hatching for main break surfaces. Scale bars: A, 100 mm; B, 50 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608763/files/figure.png	https://doi.org/10.5281/zenodo.15608763	FIG. 24. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin, Peru) in anterodorsal (A) and posterior (B) view. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 24. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602 (Chilcatay Formation, East Pisco Basin, Peru) in anterodorsal (A) and posterior (B) view. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608765/files/figure.png	https://doi.org/10.5281/zenodo.15608765	FIG. 25. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 4961 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal (A), right lateral (B), ventral (C), and posterior (D) view. Scale bar: 100 mm. Photos by Olivier Lambert.	FIG. 25. — Partial cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 4961 (Chilcatay Formation, East Pisco Basin, Peru) in dorsal (A), right lateral (B), ventral (C), and posterior (D) view. Scale bar: 100 mm. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608717/files/figure.png	https://doi.org/10.5281/zenodo.15608717	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	FIG. 1. — Geographic and geological setting: A, location of the main outcrops of the Chilcatay Formation along the southern coast of Peru; B, simplified map providing the position of Ullujaya (the type locality of Chilcacetus ullujayensis n. sp.), Roca Negra,and Zamaca (the localities of several other odontocetes described here) alongside other highly fossiliferous sites of the Ica desert; C, schematic stratigraphic column of the Cenozoic succession exposed in the East Pisco Basin; D, simplified stratigraphic section of the Chilcatay Formation in Ullujaya, showing the exact position of the two specimens of Chilcacetus ullujayensis n. sp. in the Ct1 allomember, Ct1a facies association; E, simplified stratigraphic section of the Chilcatay Formation in Roca Negra and Zamaca, showing the exact position of Chilcacetus cavirhinus Lambert, Muizon & Bianucci, 2015 MUSM 4692 in the Ct1 allomember, Ct1c facies association, and of Amphidelphis bakersfieldensis n. comb. MUSM 4691 in the Ct1 allomember, Ct1a facies association. Both sections D and E include positions of ash layers dated with 40Ar/39Ar and shell-rich beds dated with 87Sr/86Sr along with the corresponding age estimates (after Bosio et al. 2020a, b, 2022). Maps and sections modified from Bianucci et al. (2018), Di Celma et al. (2018, 2019), Bosio et al. (2020b, 2022), and Lambert et al. (2023).	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608779/files/figure.png	https://doi.org/10.5281/zenodo.15608779	APPENDIX 5. — Textured 3D model of the cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602, available at: https://doi.org/10.7934/P5641	APPENDIX 5. — Textured 3D model of the cranium of Odontoceti aff. Amphidelphis bakersfieldensis MUSM 602, available at: https://doi.org/10.7934/P5641	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
276487C62727FFBACB749B9FFDC27FFE.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/15608751/files/figure.png	https://doi.org/10.5281/zenodo.15608751	FIG. 18. — Detached left part of the basicranium of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States) in lateral (A), ventral (B), and posterior (C) view. Scale bar: 50 mm. Credits: Photos by Advait Jukar. Photos by Olivier Lambert.	FIG. 18. — Detached left part of the basicranium of Amphidelphis bakersfieldensis n. comb. YPM 13406 (holotype, Kern County, California, United States) in lateral (A), ventral (B), and posterior (C) view. Scale bar: 50 mm. Credits: Photos by Advait Jukar. Photos by Olivier Lambert.	2025-06-05	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni		Zenodo	biologists	Lambert, Olivier;Muizon, Christian de;Bennion, Rebecca F.;Urbina, Mario;Bianucci, Giovanni			
