Skip to main content
Springer Nature Link
Log in

The cranium and dentition of Khirtharia (Artiodactyla, Raoellidae): new data on a stem taxon to Cetacea

  • Research
  • Published:
Journal of Mammalian Evolution Aims and scope Submit manuscript

Abstract

Raoellid mammals are small artiodactyls from the Eocene of Asia, hypothesized to be closely related to stem Cetacea. Knowledge of the cranial and dental morphology of Raoellidae comes mostly from one species, Indohyus indirae. Here we describe new material of another raoellid genus, Khirtharia, based on material retrieved from the Kalakot area, Jammu and Kashmir. This new material, comprising an almost complete, lightly deformed cranium and a partial snout with associated partial mandible, greatly adds to our knowledge of raoellid morphology. It highlights the similarity of cranial characters with Indohyus, such as a long snout with raptorial incisors, a thick and narrow supraorbital region, a strong postorbital constriction, a triangular shaped braincase, and a thickened medial wall to the auditory bulla (involucrum). The new specimen is similar to Indohyus cranially but differs dentally in being more bunodont. The presence of these traits in two different raoellid genera suggests they may be present more broadly across Raoellidae. These characters are also observed in early cetaceans, highlighting the need to investigate their phylogenetic impact. Some cranial features support aquatic habits of members of this family.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
€32.70 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price includes VAT (Vietnam)

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

Data availability

All data generated or analyzed during this study are included in this published article and in Online Resource 1.

References

  • Amson E, Billet G, Muizon C de (2018) Evolutionary adaptation to aquatic lifestyle in extinct sloths can lead to systemic alteration of bone structure. Proc R Soc B 285:20180270

    Article  PubMed  PubMed Central  Google Scholar 

  • Barklow WE (2004) Amphibious communication with sounds in hippos, Hippopotamus amphibius. Anim Behav 68:1125–1132

    Article  Google Scholar 

  • Bhandari LL, Agarwal GC (1966) Eocene (Subathu series) of the Himalayan foothills, north India. Publ Cent Adv Stu Geol Punjab Univ 3:57–78

    Google Scholar 

  • Cooper LN, Thewissen JGM, Bajpai S, Tiwari BN (2012) Postcranial morphology and locomotion of the Eocene raoellid Indohyus (Artiodactyla: Mammalia). Hist Biol 24(3):279–310

    Google Scholar 

  • Dehm R, Oettingen-Spielberg T (1958) Paläontologische und geologische Untersuchungen im Tertiär von Pakistan. 2. Die mitteleocänen Säugetiere von Ganda Kas bei Basal in Nordwest-Pakistan. Bay Akad Wiss Math -Naturwiss Kl Abh 91:1–54

    Google Scholar 

  • Gatesy J, Geisler JH, Chang J, Buell C, Berta A, Meredith RW, Springer MS, McGowen MR (2013) A phylogenetic blueprint for a modern whale. Mol Phylogenet Evol 66(2):479–506

    Article  PubMed  Google Scholar 

  • Geisler JH, Uhen MD (2003) Morphological support for a close relationship between hippos and whales. J Vertebr Paleontol 23:991–996

    Article  Google Scholar 

  • Geisler JH, Uhen MD (2005) Phylogenetic relationships of extinct cetartiodactyls: Results of simultaneous analyses of molecular, morphological and stratigraphic data. J Mammal Evol 12:145–160

    Article  Google Scholar 

  • Gingerich PD, Russell DE (1990) Dentition of early Eocene Pakicetus (Mammalia, Cetacea). Contrib Mus Paleontol Univ Mich 28:1–20

    Google Scholar 

  • ICVGAN (International Committee on Veterinary Gross Anatomical Nomenclature) (2017). Nomina Anatomica Veterinaria. Editorial Committee of the World Association of Veterinary Anatomists, Hanover, Ghent, Columbia (MO), Rio de Janeiro.

    Google Scholar 

  • Kumar K, Loyal RS (2006) Excursion Guide on Sub-Himalayan Palaeogene Succession of Shimla Hills (Subathu–Dagshai–Kasauli Formations in Stratotype Area, Solan District, Himachal Pradesh). Wadia Institute of Himalayan Geology, Dehradun

  • Kumar K, Sahni A (1985) Eocene mammals from the Upper Subathu Group, Kashmir Himalaya, India. J Vertbr Paleontol 5:153–168

    Article  Google Scholar 

  • Kumar K, Sahni A (1986) Remingtonocetus harudiensis, new combination, a middle Eocene archaeocete (Mammalia, Cetacea) from Western Kutch, India. J Vertbr Paleontol 6:326–349

    Article  Google Scholar 

  • Lebrun R, Orliac MJ (2017) MorphoMuseuM: an online platform for publication and storage of virtual specimens. Paleontol Soc Pap 22:183–195

    Article  Google Scholar 

  • Luo Z (1998) Homology and transformation of the cetacean ectotympanic bullae. In: Thewissen JGM (ed) Evolutionary Emergence of Whales. Plenum Press, New York, pp 269–301

    Chapter  Google Scholar 

  • Mathur NS (1978) Biostratigraphical aspects of the Subathu Formation, Kumaun Himalaya. Rec Res Geol 5:96–112

    Google Scholar 

  • McGowen MR, Gatesy J, Wildman DE (2014) Molecular evolution tracks macroevolutionary transitions in Cetacea. Trends Ecol Evol 29:336–346

    Article  PubMed  Google Scholar 

  • McKenna MC, Bell SK (1997) Classification of Mammals Above the Species Level. Columbia University Press, New York

    Google Scholar 

  • Muizon C de, Billet G, Argot C, Ladevèze S, Goussard F (2015) Alcidedorbignya inopinata, a basal pantodont (Placentalia, Mammalia) from the early Palaeocene of Bolivia: anatomy, phylogeny and palaeobiology. Geodiversitas 37(4):397–634

    Article  Google Scholar 

  • Nanda AC, Kumar K (1999) Excursion guide on the Himalayan Foreland Basin, Special Publication No. 2. Wadia Institute of Himalayan Geology, Dehradun

  • Nummela AS, Hussain ST, Thewissen JGM (2006) Cranial anatomy of Pakicetidae (Cetacea, Mammalia). J Vertebr Paleontol 26:746–759

    Article  Google Scholar 

  • Orliac MJ, Ducrocq S (2012) Eocene raoellids (Mammalia, Cetartiodactyla) outside the Indian Subcontinent: palaeogeographical implications. Geol Mag 149(1):80–92

    Article  Google Scholar 

  • Orliac MJ, Thewissen JGM (2021) The endocranial cast of Indohyus (Artiodactyla, Raoellidae): the origin of the cetacean brain. J Mammal Evol 28(3):831–843

    Article  Google Scholar 

  • Orliac MJ, Waqas M, Rana R, Smith T (2024) Virtual restoration of the snout of Khirtharia inflata (Raoellidae, Artiodactyla) from the middle Eocene of northwest Himalaya. MorphoMuseuM e224:1–8

  • Patel S, Nanda AC, Orliac M, Thewissen JG (2024). Cranial anatomy of Indohyus indirae (Raoellidae), an artiodactyl from the Eocene of India, and its implications for raoellid biology. Palaeontol Electron 27(1):1–14

    Google Scholar 

  • Pilgrim GE (1940) Middle Eocene mammals from Northwest India. Proc Zool Soc Lond B 110:127–152

    Article  Google Scholar 

  • Ranga Rao A (1971) New mammals from Murree (Kalakot Zone) of the Himalayan foot hills near Kalakot, Jammu and Kashmir state, India. J Geol Soc India 12:125–134

    Google Scholar 

  • Ranga Rao A (1972) New mammalian genera and species from the Kalakot zone of Himalayan foot hills near Kalakot, Jammu and Kashmir State, India. Dir Geol Oil Natural Gas Comm Dehra Dun India Spec Pap 1:1–22

    Google Scholar 

  • Rana RS, Waqas M, Orliac MJ, Folie A, Smith A (2021) A new basal raoellid artiodactyl (Mammalia) from the middle Eocene Subathu Group of Rajouri District, Jammu and Kashmir, northwest Himalaya, India. Geobios 66:193–206

    Article  Google Scholar 

  • Sahni A, Khare SK (1971) Three new Eocene mammals from Rajouri District, Jammu and Kashmir. J Palaeontol Soc India 14:41–53

    Google Scholar 

  • Sahni A, Khare SK (1973) Additional Eocene mammals from the Subathu Formation of Jammu and Kashmir. J Palaeontol Soc India 17:31–49

    Google Scholar 

  • Singh BP, Andotra DS (2000) Barrier lagoon and tidal cycles in Palaeocene to Middle Eocene Subathu Formation, NW Himalaya, India. Tert Res 20:65–78

    Google Scholar 

  • Singh BP, Singh YR, Andotra DS, Patra A, Srivastava VK, Guruaribam V, Sijagurumayum U, Singh GP (2016) Tectonically driven late Paleocene (57.9-54.7 Ma) transgression and climatically forced latest middle Eocene (41.3-38.0 Ma) regression on the Indian subcontinent. J Asian Earth Sci 115:124–132

    Article  Google Scholar 

  • Singh P (1980) The Subathu Group of India. Geosci J. Professional Paper. 1, Navjyoti Scientific Publications, Lucknow 1–92

  • Theodor JM, Erfurt J, Métais G (2007) The earliest artiodactyls. In: Prothero DR, Foss SE (eds) The Evolution of Artiodactyla. John Hopkins University Press, Baltimore, pp. 32–58

    Google Scholar 

  • Thewissen JGM (2014) The Walking Whales: from Land to Water in Eight Million Years. University of California Press, Berkeley

    Book  Google Scholar 

  • Thewissen JGM, Cooper LN, Clementz MT, Bajpai S, Tiwari BN (2007) Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature 450(7173):1190–1194

    Article  CAS  PubMed  Google Scholar 

  • Thewissen JGM, Gingerich PD, Russell DE (1987) Artiodactyla and Perissodactyla (Mammalia) from the Early-Middle Eocene Kuldana Formation of Kohat (Pakistan). Contrib Mus Paleontol Univ Mich 27:247–274

    Google Scholar 

  • Thewissen JGM, Madar SI, Hussain ST (1996) Ambulocetus natans an Eocene cetacean (Mammalia) from Pakistan. Cour Forsch Inst Senckenberg 191:1–86

    Google Scholar 

  • Thewissen JGM, Nanda AC, Bajpai S (2020) Indohyus, endemic radiation of raoellid artiodactyls in the Eocene of India and Pakistan. In: Prasad GVR, Patnaik R (eds) Biological Consequences of Plate Tectonics. New Perspectives on Post-Gondwana Break-up—A Tribute to Ashok Sahni. Springer, Cham, pp 337–346

    Chapter  Google Scholar 

  • Thewissen JGM, Sensor JD, Clementz MT, Bajpai S (2011) Evolution of dental wear during the origin of whales. Paleobiology 37:655–669

    Article  Google Scholar 

  • Thewissen JGM, Williams EM, Hussain SM (2001) Eocene mammal faunas from northern Indo-Pakistan. J Vertebr Paleontol 21:347–366

    Article  Google Scholar 

  • Uhen MD (2007) Evolution of marine mammals: back to the sea after 300 million years. Anat Rec 290:514–522

    Article  Google Scholar 

  • Waqas M, Rana RS (2020) New Raoellidae (Artiodactyla) from the Subathu Group (Middle Eocene), Rajouri District, Jammu and Kashmir, India and their significance. Himal Geol 41:171–182

    Google Scholar 

  • West RM (1980) Middle Eocene large mammal assemblage with Tethyan affinities, Ganda Kas Region, Pakistan. J Paleontol 54:508–533

    Google Scholar 

  • Wible JR, Spaulding M (2013) On the cranial osteology of the African palm civet, Nandinia binotata (Gray, 1830) (Mammalia, Carnivora, Feliformia). Ann Carnegie Mus 82(1):1–114

    Article  Google Scholar 

Download references

Acknowledgements

We thank Nathan Vallée Gillette (RBINS) for the delicate preparation of the specimens, Julien Lalanne (RBINS) for the optical focus stacking photographs, Camille Locatelli (RBINS) and Stijn Goolaerts (RBINS) for the CT-scanning of the specimens at the RBINS facility and Renaud Lebrun (ISEM) for the access of scanning facilities (MRI platform member of the national infrastructure France-BioImaging supported by the French National Research Agency [ANR-10-INBS-04, «Investments for the future»], the LabEx CEMEB [ANR-10-LABX-0004] and NUMEV [ANR-10-LABX-0020]). This work was supported by the FYSSEN foundation, the ISEM – projet au Sud funding, and the Royal Belgian Institute of Natural Sciences.

Author information

Authors and Affiliations

  1. Institut des Sciences de l’Evolution de Montpellier, Université de Montpellier, Montpellier, France

    Mohd Waqas & Maeva J. Orliac

  2. Department of Geology, HNB Garhwal University, Srinagar Garhwal, 246174, Uttarakhand, India

    Mohd Waqas & Rajendra Singh Rana

  3. Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, 29 Rue Vautier, 1000, Brussels, Belgium

    Thierry Smith

Authors
  1. Mohd Waqas
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Thierry Smith
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Rajendra Singh Rana
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Maeva J. Orliac
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

M.W collected the specimens in the field, M.O and M.W wrote the main manuscript text, M.O and T.S prepared the figures, M.O performed the 3D segmentations. All authors reviewed and improved the manuscript.

Corresponding author

Correspondence to Maeva J. Orliac.

Ethics declarations

Declarations

The research leading to these results received funding from the FYSSEN foundation, the Institut des Sciences de l’Evolution, Montpellier (ISEM, projet au sud), and the Royal Belgian Institute of Natural Sciences. The authors have no relevant financial or non-financial interests to disclose. The authors have no competing interests to declare that are relevant to the content of this article. All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. The authors have no financial or proprietary interests in any material discussed in this article.

Competing interests

The authors declare no competing interests.

Supplementary Information

Below is the link to the electronic supplementary material.

Online Resource 1 (PDF 1100 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Waqas, M., Smith, T., Rana, R.S. et al. The cranium and dentition of Khirtharia (Artiodactyla, Raoellidae): new data on a stem taxon to Cetacea. J Mammal Evol 31, 24 (2024). https://doi.org/10.1007/s10914-024-09720-9

Download citation

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10914-024-09720-9

Keywords