Kalakocetus: NOT ‘a basal representative of Cetacea’, just Odontoceti

Quick note:
Following the typical references section in today’s blogpost see attached remarks from three reviewers and one editor associated with this Nature publication. Well worth reading if you ever have an interest in academic submission.

Complete remarks are linked here.

Back in 2016
the large reptile tree (LRT, 2340 taxa) invalidated the traditional clade ‘Cetacea‘ by showing the evolution of Indohyus and other long-snouted ‘walking whales’ like Pakicetus from sengis and tenrecs, like long-snouted Rhynchocyon and Phiomicetus – separate from baleen whales evolving from desmostylians and flat-headed hippos + oreodonts.

So papers with the phrase, ‘a basal representative of Cetacea’
in their titles have been omitting taxa pertinent to this topic.

Wagas et al 2026
described a mandible with teeth from the Middle Eocene of India (which was once connected to Madagascar, home of the tenrecs, back in the late Cretaceous 84 to 90mya). They named their new taxon, Kalakocetus, “a basal representative of Cetacea from the Eocene of India.”

You can see what little is known of Kalakocetus to scale with related taxa here.
You can see Pakicetus compared to Tenrec, Rhynchocyon and ancestral taxa back to tree shrews here on the same web page.

The authors reported,
“highly derived carnivorous teeth appear abruptly in the fossil record and the earliest evolutionary history of their dentition remain poorly understood.”

Tenrecs also have ‘highly derived carnivorous teeth’ matching shapes and patterns seen in academically recognized walking whales like Indohyus, Phiomicetus, Pakicetus and kin. Moreover their general anatomy from nose tip to tail tip are good matches.

Wait a minute! “highly derived carnivorous teeth’ are not usually found in artiodactyls. And no one noticed this anomaly.

Yesterday
we looked at a relative of Indohyus: Khirtharia, also from Eocene NW India from several of the same authors as today’s taxon.

Click on the above links to see the data and pertinent web pages.

References
Waqas, M.,  et al. (11 co-authors) 2026. A basal representative of Cetacea from the Eocene of India. Nat Ecol Evol (2026). https://doi.org/10.1038/s41559-026-03055-9

wiki/Indohyus
wiki/Khirtharia
wiki/Raoellidae
wiki/Andrewsiphius
wiki/Hemicentetes
wiki/Tenrec
wiki/Phiomicetus
wiki/Kalakocetus

researchgate.net/publication/328388746_The_triple_origin_of_whales

reptileevolution.com/reptile-tree.htm

With recent interest in what constitutes a ‘decent review’
I attach correspondence from the Nature editor and three reviewers. Even though these quotes are abridged for brevity, please note the professional tone and keen interest each reviewer gives to the manuscript.

Post-doc Romain Weppe (Montpellier France) was the second author to whom correspondence was directed from the editor.

Link to the complete Peer Review file PDF here.

You’ll find the complete PDF enlightening and will prepare you for comments to come on your own submitted manuscript, completely different in tone and length from “You didn’t look at the specimen long enough”.

Also note that all three reviewers accept the traditional artiodactyl origin of a monophyletic clade, Cetacea. So when the LRT indicated otherwise in 2016, that ‘did not fly.’
Again, remember the authors’ quote, “highly derived carnivorous teeth.”

From the editor:
“Dear Dr Weppe, Your manuscript entitled “A new fossil from India documents the earliest phase of cetacean evolution” has now been seen by three reviewers, whose comments are attached. The reviewers have raised a number of concerns which will need to be addressed before we can offer publication in Nature Ecology & Evolution. We will therefore need to see your responses to the criticisms raised and to some editorial concerns, along with a revised manuscript, before we can reach a final decision regarding publication. We therefore invite you to revise your manuscript taking into account all reviewer and editor comments. Please highlight all changes in the manuscript text file.”

From Reviewer #1
“The manuscript … offers a potentially critical window into dental changes along the   cetacean land-to-sea transition. Cetaceans (modern whales, dolphins and porpoises) have a remarkable fossil record that illustrates shifts in dentition and the body plan as terrestrial, quadrupedal artiodactyls initially became semi-aquatic and then obligatorily aquatic. The earliest cetaceans, called archaeocetes, are documented from middle Eocene rocks of the Indian subcontinent. They were semi-aquatic and had dental modifications suggesting they were probably eating a diet of fish or other meat. This is in contrast to their close relatives, raoellids, that were coeval but surprisingly consumed vegetation, as evidenced by isotopic assays. The new fossil, Kalakocetus, presented by Waqas et al bridges the gap between these two dietary modes and therefore adds critical insights into the stepwise dental changes that were critical to the ultimate success of archaeocetes in invading and successfully colonizing the marine habitat.”

“Overall, I consider this manuscript to be an essential contribution to the field and offer the following comments:”

“This is a nice contribution, but the manuscript needs polishing and greater specificity to convey the work more accurately.”

Not sure why this reviewer felt it necessary to provide a primer on whale evolution.

Reviewer #2
“Dear Editors, dear Authors, The manuscript from Waqas and colleagues encloses the description of a new fossil that doubtlessly represent a new taxon (new genus and species) of great importance for our understanding of cetacean evolution. It is accompanied by analyses to estimate the new taxon’s phylogenetic position, as well as most likely diet, and finally a reconstruction of the morphological changes associated with early cetacean diet shift. I found the analyses convincing, the manuscript well written, and the illustrations of great quality. I therefore have no major issues with this manuscript, and I recommend its publication. The importance of this fossil and its bearing for cetacean evolution ensures that this study will be relevant to a wide audience of evolutionary biologists, Nature EE seems to be an appropriate venue to do so. Except for minor issues (see below), I’d only have one more substantial recommendation for the authors, namely addressing the fact that raoellids and cetaceans are now known to be components of the same fauna.”

This reviewer summarizes the manuscript, then recommends publication, then emphasizes the importance of this discovery. Excellent form. The list of ‘minor issues’ included a careful combing on the manuscript for typos, abbreviations, etc.

Reviewer #3
“(Remarks to the Author): The authors described a mandible from a new cetacean species. Besides a phylogenetic analysis, they also applied several functional analyses. The paper is well-written and well structured, although the format (with most of the info in extended method/result or SI) is per se difficult to review. I therefore recommend it for publication, pending minor revisions. As agreed with the editor, due to time constraints, I have focused my reading (and my review) on DMTA, although I have read the whole main text and had a quick look at all SI / S Data. It can therefore be that I missed something. My main comments concern data sharing; it is quite good, but it can be even better without much effort. I detail these and other minor comments below.”

This reviewer mentions DMTA = dental microware texture analysis, which was part of the submitted manuscript.

And finally,
the good news (February 10, 2026)

From the editor:
“Dear Dr. Weppe, Thank you for submitting your revised manuscript “A new fossil from India documents the earliest phase of cetacean evolution” (NATECOLEVOL-25083002B). It has now been seen again by the original reviewers and their comments are below. The reviewers find that the paper has improved in revision, and therefore we’ll be happy in principle to publish it in Nature Ecology & Evolution, pending minor revisions to satisfy the reviewers’ final requests and to comply with our editorial and formatting guidelines.”

Reviewer #1 (Remarks to the Author):
“The authors have addressed the reviewer’s comments reasonably.”

Reviewer #2 (Remarks to the Author):
“Dear Editor, dear authors, I have now examined the reviewed manuscript and rebuttal letter. All issues raised at the previous row of reviews have been addressed, I look forward to seeing the published articled.”

Reviewer #3 (Remarks to the Author):
“The authors did a great job addressing my (and the other reviewers’) comments. The RDM part is now great! I have only two very minor comments left:”

My remarks would have included:
1. ‘please show the new specimen alongside previously described related taxa.’
2. ‘please expand the taxon list’
3. ‘highly derived carnivorous teeth?? Please explain if this is indeed an artiodactyl.’

Source: https://pterosaurheresies.wordpress.com/2026/04/30/kalakocetus-not-a-basal-representative-of-cetacea-just-odontoceti/