An international team working in Peru found the skull, the lower jaw and some teeth of what has been called 'a new raptorial sperm whale'. The experts named the animal Leviathan melvillei and dated it as 12-13 million years old.
The unusual finding is related to the teeth: more than 36 cm long and with a 12 cm diameter. These could have been used to feed on on medium-size baleen whales as Olivier Lambert - one of the researchers - suggests: "... it has the largest teeth, and possibly the most powerful bite. With such large teeth on upper and lower jaws, robust mandible and vast area of origin for jaw muscles, we think Leviathan was able to feed on large prey."
Olivier Lambert, Giovanni Bianucci, Klaas Post, Christian de Muizon, Rodolfo Salas-Gismondi, Mario Urbina, Jelle Reumer. The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru. Nature 466 (7302): 105 DOI: 10.1038/nature09067
Abstract: The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid teeth have been discovered in various Miocene localities, associated diagnostic cranial remains have not been found so far. Here we report the discovery of a new giant sperm whale from the Middle Miocene of Peru (approximately 12–13 million years ago), Leviathan melvillei, described on the basis of a skull with teeth and mandible. With a 3-m-long head, very large upper and lower teeth (maximum diameter and length of 12 cm and greater than 36 cm, respectively), robust jaws and a temporal fossa considerably larger than in Physeter, this stem physeteroid represents one of the largest raptorial predators and, to our knowledge, the biggest tetrapod bite ever found. The appearance of gigantic raptorial sperm whales in the fossil record coincides with a phase of diversification and size-range increase of the baleen-bearing mysticetes in the Miocene. We propose that Leviathan fed mostly on high-energy content medium-size baleen whales. As a top predator, together with the contemporaneous giant shark Carcharocles megalodon, it probably had a profound impact on the structuring of Miocene marine communities. The development of a vast supracranial basin in Leviathan, extending on the rostrum as in Physeter, might indicate the presence of an enlarged spermaceti organ in the former that is not associated with deep diving or obligatory suction feeding.
For more information:
Photo (c) Tony Wu: adult 'modern' sperm whale carrying the remains of a squid.
31 October 2010
27 October 2010
We did 1,343 km of navigation encompassing the whole Gulf (an area of 1,265 squared km), resulting in 13 encounters with bottlenose dolphins, 3 with monk seals, 5 with large (80+ cm) tuna, 20 with flying fish, and one with a sea turtle.
Giovanni Bearzi and Silvia Bonizzoni
Pubblicato da Giovanni Bearzi a 15:27
13 October 2010
The 2010 season in the waters of the Ligurian Sea and Pelagos Sanctuary has been impressive: 13000 km travelled at sea, totalling 905 h of navigation and 297 cetacean sightings: 210 of striped dolphins, 44 of fin whales, 32 of sperm whales, 5 of Risso’s dolphins, 4 of beaked whales and two of long-finned pilot whales. How many animals? Who knows, we are still trying to figure it out. And then sea turtles, ocean sunfish, tuna, swordfish, seabirds.
But out at sea there were not only dolphins, whales and all sort of other animals. There were people too. Participants from around the world joined the researchers on Pelagos, willing to see animals, enjoy them, contribute to their protection and being a part of our endeavors. How can we forget the volunteers crying while looking at the small striped dolphins bowriding in front of them, turning on their sides and glancing at them as if they were truly feeling a bond with the people on board. The agile and gigantic, confident and majestic sperm whales resting at the surface, dominating the resounding waves. How can we forget those who remained breathless and speechless in front of a fin whale blowing, just a few metres from our boat.
As Ralph Waldo Emerson put it, “Nothing great was ever achieved without enthusiasm”. It is always a pleasure to work with happy and enthusiastic people, curious and interested, able to spread their passion and excitement. Many thanks to all of you!
Nino, Eva, Chiara and Sabina (CSR team members)
This week was fantastic, I’ve learned so much about all kinds of animals. I would recommend this trip to anyone but I would say to book two weeks because by the time the first week is over you have just settled in and found where everything goes. Thank you to all the crew for making this trip memorable.
A stellar expedition that exceeded my expectations in many ways: from the delicious meals, to the informative conversations and lectures, the opportunity to have been a participant in these research activities has been an experience of a lifetime. Thanks for a great week of superlatives Tethys!
This week was one of the most spectacular times we have ever had. The wonderful nature, the giant animals, the life on board and the patience and kindness of the researchers are only a few points that made this time so fantastic for us. We learnt a lot about the animals in the Mediterranean Sea and when we come so close to them, we felt the beauty and the uniqueness of these wonderful animals. It is a great pleasure to find people, who watch and protect them from human foolishness and unawareness. Thank you to all of the researchers of Tethys. All of you do a very great job and we are glad to know you. We will come back again!
Heimo, Sabine and Angela (Germany)
I have had such a brilliant time onboard Pelagos! Seeing so many dolphins and whales was amazing, especially seeing the Risso’s dolphins! I have learnt so much and definitely have a greater appreciation for conserving the marine environment, I won’t eat tuna that has been fished using unsustainable methods again! Everyone has been so kind and welcoming and the food has been yummy! I definitely want to come back again next year!
I expected it to be good but it was so much better than good in so many different ways. Some moments of pure unadulterated joy that will last me forever. Thank you.
It was a really fantastic week. It was much better than we had expected. The weather was very good. The boat was nice. We had a lot of fun and we got a very good impression of the researchers’ work. They are really professional and very passionate in their work. And in addition to that they are so polite, helpful, friendly and wonderful people. They managed to do their research and involve the participants into their work at the same time. And still, there was always time for explanation and fun! We would like to come again. Thank you and stay as you are!
Christoph and Claudia (Germany)
Pubblicato da Giovanni Bearzi a 06:29
11 October 2010
I have had a wonderful week, seeing so many different dolphin behaviours and many sea birds including flamingos, cormorants and terns. Marina and Joe have made it special with their enthusiasm and anecdotes of a broad range of experiences in the field. I shall return to work refreshed and with an enhanced understanding of the importance of dolphins in their ecosystem.
It was an amazing week from several points of view – to meet so different and interesting people and to work together in such a wonderful project. I learned a lot about the dolphins, their life and behaviour, about the sea – how big, how great and at the same time how unprotected it is. When you learn something new, that really touches your mind, you start to think in a different way and consequently you change your deeds. Moreover, you try to share this experience with the other people and hopefully can make the surrounding world a little bit better. I also hope that the data we have managed to collect will be helpful for the further scientific work. This week in Vonitsa impressed me a lot and I would like to say thank you very much to Marina and Joe and all the people from our Team.
Thanks to the weather, to a great team, to the dolphins and to Greece. It was a wonderful time and experience I have got. I do not think I would be able to get such an experience anywhere else and I hope I made a tiny contribution to the process of improvement of the environment. Let’s hope that the next teams and generations see how beautiful it is. Dolphins are wonderful creatures and have their right to survive as all the rest creatures in the world. The project was organised on very high professional level, exactly what was required for the effective work and team building exercise. My personal gratitude to Marina and Joe, for their professionalism and kind attention to the team, they were able to create the right atmosphere to give the feeling to every member of the importance of their contribution. The whole team was excellent, and everyone had a chance to use his or her knowledge and experience. I learned a lot, I hope to continue to cooperate with Earthwatch institute to take part in future projects. I wish all the best and every success to Tethys in their difficult and generous task. Thanks again and all the best!
Our week in Vonitsa has been amazing. Marina’s enthusiasm for her subject (botany excluded?) and life in general made all the week a joy, not just the dolphin recording and watching. Flamingos, seagulls, schools of small fish boiling the sea waters, exploring islands and local community living, all added to the experience in which watching dolphins bow-riding was the highlight. Joe’s helpful, good-humour and interest in the work encouraged us. He and Marina worked (worked well together to make up the whole brilliant team) with an interesting group of fellow volunteers. Thank you to all who made the week possible.
Judith and George (UK)
Pubblicato da Giovanni Bearzi a 14:34
06 October 2010
Pubblicato da Giovanni Bearzi a 11:57
05 October 2010
Pubblicato da Giovanni Bearzi a 11:56
04 October 2010
After having spent a part of the summer dealing with all the logistical aspects, Silvia and I finally moved to a convenient location in the central part of the Gulf. We set up a new field station and managed to get appropriate mooring facilities. We are now ready for work at sea.
OceanCare kindly provided funding to start this new enterprise, and lent a new 100HP engine. Work in the Gulf—done in the context of a collaboration between Tethys and OceanCare—should be conducted between autumn 2010 and spring 2011. Depending on the results, we will decide how the project may unfold in future years.
Some information on dolphins in the Northern and Southern Gulfs of Evia was produced in 2003 by researchers Zafiropoulos and Merlini (*), who reported a high density of bottlenose dolphins in the Northern Gulf. Since then, however, no systematic research was conducted.
Our new study intends to complement the existing information and if possible contribute a preliminary estimate of dolphin abundance, as well as information about status and threats, which may support management action.
The work is also intended to provide insight on dolphin ecology and behaviour in different habitats. It is an exciting opportunity to get to know more about dolphins living in the coastal waters of Greece and allow for comparisons among areas exposed to a variety of human impacts, based on work that is now being conducted in four study areas (the other three being the Amvrakikos Gulf, the Inner Ionian Sea archipelago and the Gulf of Corinth).
To know more about the research done in the context of Coastal Dolphins Greece, please visit:
Giovanni Bearzi and Silvia Bonizzoni
(*) Zafiropoulos D., Merlini L. 2003. A comparative ecological study of bottlenose dolphins (Tursiops truncatus) in South and North Evoikos Gulfs. 8th International Conference on Environmental Science and Technology, Lemnos island, Greece.
Pubblicato da Giovanni Bearzi a 11:55
03 October 2010
I set out at the beginning of this experience with the aim of broadening my understanding of cetaceans and hoped to use it to gain more of an insight into the field of Cetology. I’ve always held a deep fascination for the sea and all its inhabitants. So, when I was lucky enough to be offered this opportunity to get to know it a little bit better, I was really thrilled.
After almost 8 months of waiting for the time to depart on this journey, I arrived in Vonitsa, like a sponge, ready to absorb as much as I could. I will be the first to admit that I might have glamorized the whole concept of studying dolphins in my head, during the last 8 months. However, Joan was quick to bring my head out of the clouds and put feet back down on the ground. Right from the very beginning I learned that working on a project with volunteers involved three separate but equally important skills. The first being able to help in the data collection whilst conducting surveys and then be able to analyse the photos of every encounter. The second, was being able to communicate and connect with the volunteers in a way that provided them with the means to play their own role in the projects development. The final skill was taking care of the domestic affairs. I was surprised to see the amount of effort that had to go into keeping the day-to-day functioning of the project running smoothly and tried my best to keep it that way. Although, whether I succeeded in that final respect is up to Joan. Still, all this effort paled into insignificance whenever I reflected on how lucky I was to be in a position where encounters with wild dolphins were an almost daily pleasure.
The peak of this joy was on the 18th September, in Kalamos of all places. It was business as usual at the Tethys field base. Arising early with the sunrise, we left bleary-eyed from our base in Vonitsa, in the Amvrakikos Gulf. We drove to the nearby area of Kalamos from where we were to embark on what most of us had resigned ourselves to as a survey without much hope. As we cast off from the Mytikas, Joan the principle investigator (a title given to him, much to his own distaste) drove our small rib into an ethereal mist shrouding the nearby island of Kalamos. A former watery Eden, up until 1997 had a healthy population of 150 common dolphins. Sadly, however, the population suffered a dramatic decline, from about 150 to 15 in just 15 years. This was primarily the result of overfishing, which led to the depletion of their prey. However, a mere ten minutes into our survey, Joan calls out excitedly, “Dolphins, three o’clock, horizon!” We all spin round and gaze expectantly at the area that Joan has steered the boat towards. We stare intently for the next thirty seconds and with no dorsal fin sighted, we thought perhaps Joan had been mistaken. Then, they surfaced again! Black shapes arching majestically out of the water, around 500 metres straight in front of us. Delighted, there was a collective intake of breath as the sheer size of the pod that we had found became apparent. At least 10 individuals were cruising along in front of the boat. However, the best was yet to come. Joan calls out “They’re common dolphins!”. Utterly astonished, we all jumped to our stations, Joan and myself yelling out instructions. Joan’s excitement, infectious. Elated calls from our volunteers began raining in providing us valuable information on dolphin numbers and location with respect to our boat, by putting into practice the well rehearsed procedures, originally taught role-playing on the beach back in Vonitsa and honed during a week spent observing the bottlenose dolphins of the Amvrakikos Gulf. We were lucky enough to remain with them for the next three hours, trying to collect as much data as possible on this important encounter. We watched with delight as they lounged about, just stretching near the surface. The day was topped off by a sighting of a newborn common dolphin, who like any regular kid, was bursting with energy keeping the adults from resting. However, despite the feeling of euphoria on board, the passing-by of two large bottom trawlers, heading to their fishing grounds, provided a sobering reminder that lessons had still not been learnt.
During the journey back to port, the atmosphere onboard the zodiac was palpable. Each member talked animatedly about such and such a sighting that they had had, despite the fact that we had all seen the same. Finally, it was with a feeling of great satisfaction, contentment and pride that we all disembarked from the boat. We drove back to Vonitsa exhausted, but with the knowledge that we had all witnessed something special.
For me personally, this experience was the culmination of three years of hard work in getting to where I hoped to be and sheer good luck that I had been offered this opportunity. I write this with two weeks of this incredible adventure to go and feel incredibly privileged to have had the opportunity to meet such a wide range of people from all over the world; to be able to work with such a beautiful species in their natural environment; and to have been taught so much by Joan and Marina, who, together, offer a staggering amount of knowledge and insight. They have both, each in their own unique and completely different way, conveyed a feeling that will be hard to forget. I fear I have been bitten by the same "bug" and it will be with a heavy heart that I finally leave to return to England, but also a content one, knowing that this experience has been everything that I could have wished it to be.
Research assistant, Coastal Dolphins Greece
Pubblicato da Giovanni Bearzi a 11:54
02 October 2010
The dolphin research project in the Gulf of Corinth has recently concluded its second research season, scoring a total of 61 dolphin sightings.
We had many pleasant encounters with marine life. We saw all four cetacean species that inhabit the Gulf: bottlenose, striped, short-beaked common and a single Risso’s dolphin.
And also 402 encounters with jellyfish Cothyloriza tubercolata, 23 with loggerhead turtles Caretta caretta, 82 with tuna and 5 with swordfish.
Happy and satisfied about the work done this year, we are grateful to all the volunteers who participated in the field courses, helped us with the research and shared with us every single moment at sea.
A big THANK YOU to our 63 volunteers who came from 16 nations: Australia, Canada, France, Germany, Greece, Ireland, Italy, New Zealand, Norway, Poland, Portugal, Singapore, Spain, Switzerland, UK, and USA:
Frédéric, Laurence, Jillian, Christine, Kate, Sacha, Joanna, Ellis, Ann, Nathalie, Khai Lin, Amanda, Valentina, Rachel, Iris, Graham, Joy, Chrystelle, Lisbet, Katrine, Cornelia, Kate, Jamie, Dagmar, Chloe, Allan, Marie-Eve, Merry, Aislinn, Siobhan, Mirjam, Laura, Riccardo, Dominique, Emily, Karen, Jakub, Valentina, Christina, Russell, Gabriella, Dimitiros, Claudia, Nicole, Andrea, Frédéric, Alison, Suzanne, Marta, Nathan, Steven, Laura, Beatrice, Kathryn, Joana, Ana Caterina, Philipp, Lydia, Yasmine, Gabriele, Lois, Pierandrea, and Jennifer (in order of participation).
Silvia and the Hellenic Dolphins team 2010
Updated information about Coastal Dolphins Greece can be found HERE.
The expedition briefing for the research season 2011 is already ONLINE.
Pubblicato da Silvia Bonizzoni a 15:16