The lagomorphs (order Lagomorpha, infraclass Eutheria) form a clade that now comprises the rabbits and hares (family Leporidae) and the pikas (family Ochotonidae).
A frequently-cited phylogenetic analysis of the stem-Lagomorpha is that of Asher et al (2005). However, it contains only a few species; a study based on more species, but consistent with the results of Asher et al (2005), is presented in Lopatin and Averianov (2021). The latter study provides the basis for the time tree shown below:
A frequently-cited phylogenetic analysis of the stem-Lagomorpha is that of Asher et al (2005). However, it contains only a few species; a study based on more species, but consistent with the results of Asher et al (2005), is presented in Lopatin and Averianov (2021). The latter study provides the basis for the time tree shown below:
Figure 1. Time tree of the stem-Lagomorpha
The oldest known member of the lagomorph stem group is Mimotona wana, described from the Middle Paleocene Upper Member of the Doumu Formation of Qianshan, Anhui, China (Li et al, 2016). Unfortunately, no images are available in the public domain either for this species or for most of the other members of the stem group. The few that are available are shown below (for a larger view, click on image):
Names in red indicate that the fossil is younger than the oldest known crown-group fossil.
Figure 2. Images of stem-Lagomorpha
Obviously, no trends can be discerned with such a limited set of images.
The oldest known member of the crown-Lagomorpha is represented by unnamed leporid fossils described from the Early Eocene (Middle Ypresian) Cambay Shale at the Vastan lignite mine, Gujarat, India (Rose et al, 2008; Benton et al, 2015). No public-domain images are available.
The oldest known member of the crown-Lagomorpha is represented by unnamed leporid fossils described from the Early Eocene (Middle Ypresian) Cambay Shale at the Vastan lignite mine, Gujarat, India (Rose et al, 2008; Benton et al, 2015). No public-domain images are available.
References
Asher, R. J., Meng, J., Wible, J. R., McKenna, M. C., Rougier, G. W., Dashzeveg, D., & Novacek, M. J. (2005). Stem Lagomorpha and the antiquity of Glires. Science, 307(5712), 1091-1094.
Benton, M. J., Donoghue, P. C., Asher, R. J., Friedman, M., Near, T. J., & Vinther, J. (2015). Constraints on the timescale of animal evolutionary history. Palaeontologia Electronica, 18(1), 1-106.
Li, C. K., Wang, Y. Q., Zhang, Z. Q., Mao, F. Y., & Meng, J. (2016). A new mimotonidan Mina hui (Mammalia, Glires) from the Middle Paleocene of Qianshan, Anhui, China. Vert PalAsiat, 54(2), 121-136.
Lopatin, A. V., & Averianov, A. O. (2021). Arnebolagus, the oldest eulagomorph, and phylogenetic relationships within the Eocene Eulagomorpha new clade (Mammalia, Duplicidentata). Journal of Paleontology, 95(2), 394-405.
Meng, J., Hu, Y., & Li, C. (2003). The osteology of Rhombomylus (Mammalia, Glires): implications for phylogeny and evolution of Glires. Bulletin of the American Museum of Natural History, 2003(275), 1-247.
Rose, K. D., DeLeon, V. B., Missiaen, P., Rana, R. S., Sahni, A., Singh, L., & Smith, T. (2008). Early Eocene lagomorph (Mammalia) from Western India and the early diversification of Lagomorpha. Proceedings of the Royal Society B: Biological Sciences, 275(1639), 1203-1208.
Benton, M. J., Donoghue, P. C., Asher, R. J., Friedman, M., Near, T. J., & Vinther, J. (2015). Constraints on the timescale of animal evolutionary history. Palaeontologia Electronica, 18(1), 1-106.
Li, C. K., Wang, Y. Q., Zhang, Z. Q., Mao, F. Y., & Meng, J. (2016). A new mimotonidan Mina hui (Mammalia, Glires) from the Middle Paleocene of Qianshan, Anhui, China. Vert PalAsiat, 54(2), 121-136.
Lopatin, A. V., & Averianov, A. O. (2021). Arnebolagus, the oldest eulagomorph, and phylogenetic relationships within the Eocene Eulagomorpha new clade (Mammalia, Duplicidentata). Journal of Paleontology, 95(2), 394-405.
Meng, J., Hu, Y., & Li, C. (2003). The osteology of Rhombomylus (Mammalia, Glires): implications for phylogeny and evolution of Glires. Bulletin of the American Museum of Natural History, 2003(275), 1-247.
Rose, K. D., DeLeon, V. B., Missiaen, P., Rana, R. S., Sahni, A., Singh, L., & Smith, T. (2008). Early Eocene lagomorph (Mammalia) from Western India and the early diversification of Lagomorpha. Proceedings of the Royal Society B: Biological Sciences, 275(1639), 1203-1208.
Image credits – stem-Lagomorpha
- Header (Indian hare, Lepus nigricollis): N. A. Naseer / www.nilgirimarten.com / [email protected], CC BY-SA 2.5 IN <https://creativecommons.org/licenses/by-sa/2.5/in/deed.en>, via Wikimedia Commons
- Figure 2 (Gomphos cf. G. elkema): Open Access article Yo, K., Hoffman, E. A., O'Leary, M. A., & Novacek, M. J. (2022). A new Early Paleogene fossil mammal locality in the central-eastern Nemegt Basin, Gobi Desert, Mongolia, and notes on mammalian biostratigraphy. Journal of Paleontology, 1-24.
- Figure 2 (Gomphos elkema): Nobu Tamura, under Creative Commons Attribution ShareAlike (CC BY-SA) license
- Figure 2 (Gobiolagus aliwusuensis): Open Access article Li, Q., Wang, Y. Q., & Fostowicz-Frelik, Ł. (2016). Small Mammal Fauna from Wulanhuxiu (Nei Mongol, China) Implies the Irdinmanhan—Sharamurunian (Eocene) Faunal Turnover. Acta Palaeontologica Polonica, 61(4), 759-776.
- Figure 2 (Palaeolagus haydeni, fossil): Open Access article Wolniewicz, A. S., & Fostowicz-Frelik, Ł. (2021). CT-informed skull osteology of Palaeolagus haydeni (Mammalia: Lagomorpha) and its bearing on the reconstruction of the early lagomorph body plan. Frontiers in Ecology and Evolution, 9, 634757.
- Figure 2 (Palaeolagus haydeni, life restoration): Nobu Tamura, under Creative Commons Attribution ShareAlike (CC BY-SA) license