The age of the Sooke Formation on the southern coast of Vancouver Island, British Columbia, Canada, has long been controversial. Prior paleomagnetic studies have produced a puzzling counterclockwise tectonic rotation on the underlying Eocene volcanic basement rocks, and no conclusive results on the Sooke Formation itself. We took 21 samples in four sites in the fossiliferous portion of the Sooke Formation west of Sooke Bay from the mouth of Muir Creek to the mouth of Sandcut Creek. After both alternating field (AF) and thermal demagnetization, the Sooke Formation produces a single-component remanence, held largely in magnetite, which is entirely reversed and rotated counterclockwise by 35° ± 12°. This is consistent with earlier results and shows that the rotation is real and not due to tectonic tilting, since the Sooke Formation in this region has almost no dip. This rotational signature is also consistent with counterclockwise rotations obtained from the northeast tip of the Olympic Peninsula in the Port Townsend volcanics and the Eocene–Oligocene sediments of the Quimper Peninsula. The reversed magnetozone of the Sooke sections sampled is best correlated with Chron C6Cr (24.1–24.8 Ma) or latest Oligocene in age, based on the most recent work on the Liracassis apta Zone molluscan fauna, and also a number of unique marine mammals found in the same reversed magnetozone in Washington and Oregon.

A partial articulated skeleton of a desmostylian was found in siltstone of the Sooke Formation in the streambed at the mouth of the Sombrio River in Juan De Fuca Provincial Park, Vancouver Island, British Columbia, Canada. Another exposure of the Sooke Formation southeast of the locality has been dated to Chron C6Cr age, 24.1-24.8 Ma. This specimen includes the left side of the skull, two molars, a premolar, canines, partial scapula, nearly complete humerus, and numerous vertebrae and ribs. Molar characteristics are the same as material of Behemotops proteus from the Pysht Formation of Washington State, which is near the type locality of Behemotops proteus of the upper Oligocene Pysht Formation, Washington State. Previous specimens of B. proteus were limited to lower jaws and portions of the upper and lower postcanine dentitions. The slightly smaller Behemotops katsuiei from Japan is known from more elements, yet its cranial material is limited to the posterior portion of the cranium and a small portion of the zygomatic arch. This new material allows us to see that Behemotops cf. B. proteus had cranial features much like those seen in Cornwallius sookensis of North America. These include a postorbital process of the jugal, with the zygomatic process of the squamosal not dorsally expanded, a concave hard palate, enlarged canine tusks that point ventrally, and a narrow, curved incisor arcade on a narrow rostrum. This is different from specimens previously referred to as Behemotops emlongi and then synonymized with B. proteus, which have a broad symphysis with large tusks. These specimens formerly known as B. emlongi are now referred to a new genus.http://zoobank.org/urn:lsid:zoobank.