Northern Right Whale Dolphin Skull Replica

Description

Northern right whale dolphin skull replica is museum-quality polyurethane resin cast from CAS:MAM:25549; Lissodelphis borealis; Adult female; Field # WJK 516; 22 November 1994; 3.0 miles South of Pajaro River, Monterey Bay, Santa Cruz County, California (salvaged from a stranding event). 2-part skull (separate cranium and mandible). 1:1 scale (life-size). Made in USA.

Northern right whale skull Replica Specifications

• Length: 18.0 inches (45.7 cm)
• Width: 8.0 inches (20.3 cm)
• Height: 8.0 inches (20.3 cm) (includes cranium and mandible attached)
• Scale: 1:1 scale (life-size)
• Replica Weight (Net): 4.0 lbs (1.8 kg)
• Shipping Weight (Gross): 9.0 lbs (4.1 kg)
• Components: 2-part skull (separate cranium and mandible)
• Teeth Count: 175 total (44 upper left, 44 upper right, 43 lower left, 44 lower right)
• Cranium Length: 18.0 inches (45.7 cm)
• Cranium Width: 8.0 inches (20.3 cm)
• Mandible Length: 15.5 inches (39.4 cm)
• Mandible Height: 2.5 inches (6.4 cm)
• Rostrum Length: 10.0 inches (25.4 cm)
• Rostrum Width (at base): 3.7 inches (9.5 cm)
• Orbital Width (Eye Sockets): 7.5 inches (19.1 cm)
• Orbit Diameter: 1.7 inches (4.3 cm)
• External Nares Width: 1.9 inches (4.8 cm)
• Temporal Fossa Length: 2.2 inches (5.6 cm)
• Zygomatic Width: 7.9 inches (20.1 cm)

Northern right whale dolphin Anatomy

The northern right whale dolphin is a strikingly slender and elegant cetacean of the North Pacific. The California Academy of Sciences specimen highlights the streamlined skeletal adaptations of this high-speed swimmer.

The Elongated Rostrum

• The skull features a notably long and narrow rostrum. This adaptation supports a streamlined head shape, which reduces drag as the dolphin moves through the water. Furthermore, the transition from the rostrum to the braincase is smooth and gradual, unlike many other delphinids.

Teeth Count and Morphology

• This replica accurately represents the dentition of the species. The Northern right whale dolphin possesses 37 to 54 pairs of small, sharply pointed, functional teeth in both jaws. These teeth are designed for grasping slippery prey, such as squid and small mesopelagic fish.

The Absence of a Dorsal Fin

• While not a cranial feature, the skeletal morphology reflects the dolphin’s unique lack of a dorsal fin. This anatomical absence allows for an incredibly smooth dorsal profile. Consequently, the streamlined symmetry of the cranium and the alignment of the cervical vertebrae mirror this adaptation.

Symmetry and Echolocation

• The skull exhibits typical cetacean asymmetry, particularly around the narial openings. This structural arrangement supports the complex soft tissue of the melon and nasal sacs, which produce and focus high-frequency sound waves for echolocation.

Deep Water Foraging

• The delicate yet dense bone structure of the skull reflects a life spent in temperate to sub-arctic waters. Because these dolphins dive to significant depths to feed, they require a skull that can handle varying pressure changes.

The Finless Profile

• The name “right whale dolphin” derives from the right whale, which also lacks a dorsal fin. The skull’s sleek profile and the lack of a prominent melon-crested vertex highlight the evolutionary path of this species toward extreme hydrodynamic efficiency.

Scientific Classification

• Domain: Eukaryota
• Kingdom: Animalia
• Phylum: Chordata
• Class: Mammalia
• Order: Artiodactyla
• Infraorder: Cetacea
• Suborder: Odontoceti
• Family: Delphinidae
• Genus: Lissodelphis
• Species: L. borealis
• Binomial name: Lissodelphis borealis (Peale, 1848)
• Conservation status: Least Concern (IUCN 3.1), CITES Appendix II

For a complete perspective on local marine species, view the Risso’s dolphin skull replica to observe the robust, blunt-snouted cranial features of its larger North Pacific school-mate.

The northern right whale skull is molded from  California Academy of Sciences specimen CAS MAM 25549; Lissodelphis borealis; Adult female; Field # WJK 516; 22 November 1994; 3.0 miles South of Pajaro River, Monterey Bay, Santa Cruz County, California (salvaged from a stranding event).