Rare spade-toothed whale autopsy unveils prehistoric hints
This article concerns a five-metre marine mammal identified as the spade-toothed whale (Mesoplodon traversii). During the first autopsy of this individual, scientists discovered many new details, such as vestigial teeth, indicating that it once lived on land.
The world’s first autopsy of this very rare whale enabled the indigenous people and conservation scientists in New Zealand to learn more about the Mesoplodon traversii, or spade-toothed whale. The whale was found on the shores of New Zealand a few months ago. No one has ever seen a live marine mammal of this species; until now, this individual had been seen six times, and only this specimen was in good enough condition to examine.
The whale had vestigial teeth and nine stomach chambers
Research on the marine mammal's body lasted a week and was conducted by Te Rūnanga o Ōtākou in collaboration with the Department of Conservation Te Papa Atawhai, with support from the Tūhura Otago Museum and the University of Otago Whakaihu Waka. Rachel Wesley from Rūnanga, quoted by the Department of Conservation (DOC) in New Zealand, emphasised that this process allowed the integration of traditional native knowledge with Western science, enabling a better understanding of the whale's behaviour.
The section was led by Anton van Helden, marine science advisor at DOC. The study also involved scientists from New Zealand and three prominent American marine biologists. Van Helden stated that many new discoveries were made, including findings of tiny vestigial teeth in the upper jaw. These small teeth reveal more about the evolutionary history of this species, suggesting that it may have once lived on land. Additionally, scientists discovered that the whale has nine stomach chambers. Within them, they found squid beaks, lenses of their eyes, and other unspecified organism parts.
Scientists found the cause of death of the mammal
Furthermore, structures related to feeding and the sounds made by the whale were identified. Various muscles and organs were described and measured, which will help identify the species and compare it with others. The whale was named Ōnumia, referring to the place where it was found in the Taiari Native Reserve in New Zealand, emphasizing its traditional connection with the environment and cultural heritage.
Van Helden, quoted by the Department of Conservation (DOC) in New Zealand, assumes that head and neck injuries, numerous bruises, and a fractured jaw suggest trauma that could have caused the whale's death. "We don’t know, but we suspect there must have been some sort of trauma, but what caused that could be anyone’s guess," said DOC. Scientists now intend to analyse the collected data and publish the results in collaboration with the New Zealand organisation Te Rūnanga o Ōtākou. "It’s a week I’ll never forget in my life, it’s certainly a highlight and it’s the start of the storytelling around this beautiful animal," said van Helden.
Spade-toothed whales (Mesoplodon traversii) are a little-known group of whales, named for their dolphin-like beaks. The waters around New Zealand are home to 13 of the 24 known species of these marine mammals.
