![\"Scaphokogia](\"https:\/\/cdn.sci.news\/images\/enlarge14\/image_15184e-Scaphokogia-huachafo.jpg\")
<\/a><\/p>\nScaphokogia huachafo was about 2.7 m (9 feet) long; the entire structure of its skull and neck was designed to point its snout directly toward the seafloor. Image credit: Jaime Bran Sarmiento.<\/p>\n
Lopsided skulls are common among toothed whales, where asymmetry is linked to the production of sound and echolocation.<\/p>\n
But the newly described species, named Scaphokogia huachafo, took it further: both of its external bony nostrils are shifted to the left of the skull\u2019s midline, and the left one is considerably larger than the right; the bones around the left and right eye sockets also differ markedly in shape.<\/p>\n
\u201cWhen we looked at the proportions of this whale \u2014 with its face strongly shifted to the left and its oversized, downward-curving snout \u2014 it broke every rule of symmetry and elegance seen in living cetaceans,\u201d said Dr. Aldo Benites-Palomino, a vertebrate paleontologist at the GeoZentrum Nordbayern.<\/p>\n
The nearly complete skull of Scaphokogia huachafo was found in the mid-1990s at Aguada de Lomas in the Sacaco basin in Arequipa, Peru, in layers of the Pisco Formation deposited between 6.3 and 5.6 million years ago.<\/p>\n
\u201cThe initial suspicion with skulls this distorted is always taphonomy \u2014 that the specimen may have been flattened or twisted by sediment pressure over millions of years,\u201d Dr. Benites-Palomino said.<\/p>\n
\u201cBut the sutures are fully closed, and there are no fractures, pathologies or deformations elsewhere on the skull. This was genuine biology, not a result of poor preservation.\u201d<\/p>\n
To compare Scaphokogia huachafo\u2019s skull with those of other whales, the researchers built a new set of 3D measurements focused on the face and ran statistical analyses on 31 species.<\/p>\n
The genus Scaphokogia, which includes the new member and two relatives, emerged as the most asymmetric group of cetaceans in the sample.<\/p>\n
The animal\u2019s most striking feature may be its snout: a massive, tube-shaped rostrum made of dense bone and reinforced by ossified cartilage, angled steeply downward at about 31 degrees from the skull\u2019s main axis.<\/p>\n
Heavy bone in the skull \u2014 a trait seen in manatees, walruses and some early whales that fed on the bottom \u2014 helps animals control their buoyancy, and that the dense snout probably shifted the whale\u2019s center of gravity forward.<\/p>\n
Scaphokogia huachafo\u2019s second, related specimen preserving the first neck vertebra allowed the team to estimate how far the head could tilt.<\/p>\n
Its neck joint appears to have allowed substantial downward flexion, and its asymmetry suggests the head moved along a curved path rather than a straight up-and-down one.<\/p>\n
Taken together, the scientists propose that Scaphokogia huachafo was a specialized bottom feeder that foraged along the floor of shallow coastal waters.<\/p>\n
Because the animal appears to lack the specialized facial structures that many bottom-feeding mammals use to find food, it may have relied on unusual adaptations for echolocation to detect prey in soft sediment.<\/p>\n
\u201cThe entire cranio-cervical complex is modified to point the snout directly toward the bottom,\u201d said Dr. Gabriel Aguirre-Fern\u00e1ndez, a paleontologist at the University of Zurich.<\/p>\n
\u201cThe combination of dense bone, the downward-curving snout and the flexible neck articulation allowed the animal to move directly above the seabed and feed close to the sediment.<\/p>\n