Follow named fossils, separate specimen assemblages and living molecular datasets while keeping anatomy, ecology, topology, model time and COL26.8 naming coverage distinct.
Each step names its evidence claims, with references below. Interactive Explorer states are available in the full application; the narrative remains an editorial synthesis.
RR 207 and RR 208 skulls, separate dense limb bones and tooth isotopes support aquatic wading and raoellid affinity. They are not one skeleton, crown whales or proof that Indohyus directly became a whale.
Specimens, ecological interpretation and matrix placement remain separate evidence levels.
claim:event:indohyus-aquatic-raoellid-evidencePakicetus skull H-GSP 96231 and separately catalogued postcranial bones from Locality 62 support a terrestrial body plan. The published outline is a composite, not one articulated animal or a direct ancestor.
The 2001 morphology tree and the independent 1999 retroposon tree answer different sampled questions.
claim:event:pakicetus-composite-terrestrial-skeletonH-GSP 18507 preserves an amphibious combination of vertebral and limb anatomy. Otter-like swimming and sea-lion-like terrestrial motion are functional models, not observed strokes or gait.
A named specimen can constrain mechanical possibility without recording behaviour.
claim:event:ambulocetus-holotype-locomotionMUSM 3580 fixes a roughly 42.6 Ma protocetid occurrence in Peru and preserves weight-bearing anatomy. Its walking, swimming and westward Atlantic dispersal narratives are tested interpretations, not a filmed journey.
The paper explicitly leaves an eastward route and the presence of a tail fluke unresolved.
claim:event:peregocetus-holotype-amphibious-dispersalBasilosaurus retains a miniature jointed pelvic limb and foot, and UM 93231 preserves measurable femoral microstructure. Neither establishes terrestrial locomotion; copulatory use remains inferred.
Preserved anatomy, measured tissue and proposed function are three distinct claims.
claim:event:basilosaurus-hind-limb-specimensCGM 60584 records unfused sacrals, no weight-bearing sacroiliac joint, posterior vertebral elongation and reduced limbs. Greater tail propulsion is inferred, while a fluke is doubtful and not preserved.
The source itself discloses conflicting age indicators around the Bartonian–Priabonian boundary.
claim:event:aegicetus-holotype-tail-propulsionIndependent retroposon insertions support Hippopotamidae as the living sister group of Cetacea. The sampled topology does not identify a direct ancestor, date the split or place every fossil relative.
Molecular topology and fossil character placement remain independently inspectable.
claim:event:whale-hippo-retroposon-topologyThe 42,335-character supermatrix sampled 87 of 89 cetacean species recognized in 2009. Its tree and clock estimates are model results, whereas COL26.8 is the pinned authority for current accepted-name routing.
COL26.8 routes 503 strictly accepted species through the package's exact Artiodactyla and Cetacea usage roots; that is naming coverage, not 503 molecular trees, fossil dossiers or reviewed ranges.
claim:event:extant-cetacean-supermatrix-tree