Color Vision Discovered in 300 Mya Fish

According to Dr. Gengo Tanaka, the fossil below was found about 50 years ago.

“I have a friend [who owns a] fossil shop,” he wrote in an email. “I bought this specimen from him.”

Dr. Tanaka explained that his friend attributed the fossil find to his father, who discovered it in a quarry five decades ago.

It’s a small fish known as Acanthodes bridge, and it is thought to have lived in shallow waters 300 million years ago in what is now Kansas.

 

Acanthodes bridge - Tanaka, et al

[image of fossilized Acanthodes bridge, courtesy of the Natural History Museum, London]

 

It might be a little fish, but it is providing enormous and exciting information about the evolution of color vision.

In their recent paper, Dr. Gengo Tanaka of Kumamoto UniversityProfessor Andrew Parker of the Natural History Museum, London and 13 other scientists describe evidence of color vision 100 million years earlier than previously known.  They are the first to record fossil rods and cones—the cells responsible for enabling sight.

“The soft tissue of eyes are usually the first to decompose when an animal dies, and before they are fossilized. In our fish, however,” wrote Professor Parker,  “the soft tissue was preserved before burial (by sediment) and turning to rock. The original organic material has been altered (but in some cases not too much), although remains relatively soft.”

Using SEM (scanning electron microscope) and TEM (transmission electron microscopy), the scientists studied the fossil eyes in more depth.  They compared rods and cones of 509 retinal cells, obtained from the fossil itself and from existing freshwater fish.  Cones within the eye are the key to color vision, although they assert that the discovery of opsins in the fossil record would provide “conclusive evidence” for such vision.

“Cone cells are those responsible for colour vision in extant animals,” Professor Parker further explained. “They contain the opsins that react to different wavelengths of light.”

When asked if he expected to find color vision in this fossil, Dr. Tanaka wrote, “I have discovered fossilized rod and cones in several Cenozoic fishes. So, I expected that we could discover fossilized rod and cone cells in other specimens.”

Similarly, Professor Parker wrote, “I would expect to find colour vision in the geological record at some point, but I did not expect when.”

Acanthodes bridge - eye detail

 

[details of Acanthodes bridge, courtesy of the Natural History Museum, London; a: Complete dorsoventrally compressed specimen, b: details of the head region, c: details of right eye]

“We were a team interested in the emergence and history of vision, when Gengo [Tanaka] found the fossil fish,” he continued, describing how it came to pass that these 15 scientists collaborated on the paper.

But why would color vision be significant for a species such as Acanthodes bridge?

“That such ancient fish had colour vision tells us that the type of ecologies and behaviours that exist today, where light plays a major role, were also in place 300 million years ago. For the fish, they could distinguish predators and prey with greater accuracy and in some cases crack the camouflage of these animals.”

“This is the first time that colour vision has been identified in any extinct animal, regardless of geological age,” he wrote. “It suggests that our modern behavioural system, or way of living, where colour plays a major role, has been in place over at least 300 million years.”

“This can explain,” he continued, “why things have changed little over that period: predators and prey have changed form in some ways, but the balance of the different types of animals and plants living together has remained similar.  Triceratops has been replaced with rhinos, ichthyosaurs replaced by dolphins, but their roles in the ecosystem are similar. That they saw in the same way helps us to understand this.”

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An enormous thank you to Chloe Kemberry, Dr. Gengo Tanaka and Dr. Andrew Parker!  What a great pleasure connecting with you about such an exciting discovery!

Paper referenced:

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Meet Lyuba – Mummified Baby Mammoth in London

“She’s beautiful.”

So exclaimed Professor Adrian Lister upon seeing Lyuba as the lid to her crate was first opened in London. Lyuba is a 42,000-year-old baby mammoth, and her state of preservation is breathtaking.

”It was an emotional experience to be face-to-face with a baby mammoth from the Ice Age,” Professor Lister said. “I’m so thrilled that our visitors will be able to experience that, too.”

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[image of Professor Adrian Lister with Lyuba, courtesy of Natural History Museum, London]

Her discovery occurred in 2006, thanks to a family of Nenets reindeer herders in Siberia. Lyuba was initially found–her body partially exposed in the snow–by Yuri Khudi’s son. She was recovered in the spring of 2007, and she is named after Mr. Khudi’s wife.

NHM-YuriKhudiSon

[image of Yuri Khudi and son, courtesy of Natural History Museum, London]

If you are in London, you can actually see her on exhibit in Mammoths: Ice Age Giants currently at the Natural History Museum.

Mammoths: Ice Age Giants is a traveling exhibit from The Field Museum, Chicago. Since 2010, it has been seen throughout the United States (albeit under a slightly different title), but most museums have included a replica of the baby mammoth.

LyubainBoston

 

[image of Lyuba replica, taken by the author’s cellphone at the exhibit in Boston, 2012]

The replica is remarkable. But the opportunity to see Lyuba herself is extraordinary.

When asked how the Natural History Museum was able to obtain the actual mammoth, Professor Lister wrote, “The Museum worked closely with Lyuba’s home institution, the Shemanovsky Museum – Exhibition Complex in Siberia, Russia to get the opportunity to showcase Lyuba as the star of the show in Mammoths: Ice Age Giants. This involved complex contract negotiations and we are very grateful to the Shemanovsky Museum for the loan of such an important specimen.”

Hilary Hansen, one of the Field Museum’s Traveling Exhibition Managers, explained that only one of the US museums has been able to showcase Lyuba thus far.

Surprisingly, the reason is not related to cost.

“[T]he Russian government has a moratorium on loans to the US,” she wrote, “so only international venues get to host her.”

(You can read more about the origins of this moratorium here: http://www.nytimes.com/2011/02/03/arts/design/03museum.html)

And how does one ship and display such a rare and enormously valuable specimen?

It was explained that Lyuba has been thawed since discovery, but her body was essentially freeze-dried over the course of her 42,000 years of burial. She traveled to London in a purpose built wooden case which has padding/foam fitted specifically to her body inside so as to protect her during travel. Within the exhibition, she will be displayed in a climate-controlled and sealed case.

NHM-LyubaVisitors

[image of Lyuba and visitors, courtesy of Natural History Museum, London]

So much has been learned about mammoths since her discovery. Through CT scans, autopsies, and other tests, scientists have been able to ascertain more about her diet specifically and mammoth biology in general.

NHM-LyubaScientistsRussia

NHM-LyubaScientistsLab

[images of Lyuba and scientists, courtesy of Natural History Museum, London]

 

An exciting example is described in Professor Lister’s latest book, Mammoths and Mastodons of the Ice Age: the discovery of a pharyngeal pouch between the larynx and the back of her tongue. He discusses the relatively recent knowledge of this anatomical feature in today’s elephants. The pharyngeal pouch can be used for communication and to store water. Elephants in Namibia, he explains, have been seen reaching into their mouths with their trunks and spraying themselves with water they had drunk hours before. (page 80)

Pieces of material believed to be partially digested milk from Lyuba’s mother were found in her stomach (page 84), and her intestinal contents point to a practice used in today’s elephants as well: eating adult elephant feces as a way to introduce needed bacteria for digestion. (pages 84-85)

These are the kinds of exciting details one can explore in this exhibit. Using interactive displays, fossils, sculptures and other artwork, this exhibit not only introduces the visitor to some of the fascinating research being conducted today, but also summarizes some of what we’ve learned about proboscidea to date.

There is a video describing Lyuba’s discovery, and another explaining the remarkable details one can learn from mammoth tusks, both of which feature Dr. Daniel Fisher of the University of Michigan (one of the original scientists who studied Lyuba). There are videos behind possible mammoth behavior, as well as the types of ancient vegetation discovered in soil specimens.

Life-sized models of Pleistocene fauna, including a short-faced bear, a saber-toothed cat and an enormous Columbian mammoth, give added depth to what most would only see in their fossil remains.

Columbian mammoth replica

[image of Columbian mammoth model, courtesy of Natural History Museum, London]

Artwork can be found throughout the exhibit. In a striking display of the diversity of these animals, a sculpture of a dwarf mammoth stands beside a bas-relief of an elephant, a mastodon and a Columbian mammoth. Full-sized fleshed-out sculptures of proboscidean heads—species that lived prior to mammoths and mastodons—extend from the wall.

And fossils—numerous teeth, skulls, tusks and bones—from mammoths, mastodons and other Pleistocene animals can be seen throughout. A cast of the Hyde Park mastodon from New York gives visitors a chance to walk around a complete fossil and see it from every angle. The replica of a mammoth fossil in-situ lies below a time-lapse video of what a particular landscape might have looked like from the time of that mammoth to the present day.

NHM-Mastodon

[image of Hyde Park mastodon cast, courtesy of Natural History Museum, London]

The exhibit is geared toward all ages, with activities for children through adults, and having prior knowledge of mammoths or paleontology is not a prerequisite.

“A key element of the exhibition for the family-focused audience is the interactive activities,” wrote Professor Lister, “such as feeling the weight of the food a mammoth ate in one day, trunk moving and tusk jousting.”

Given its popularity and the success with which it introduces a wide variety of people to the subject, one might wonder how the exhibit took shape.

“The idea originated from staff at the Field Museum several years ago. It was one of several ideas that came about during a process of brainstorming ideas,” Hilary Hansen explained. “The other topics that came about were George Washington Carver, natural disasters, and biomimicry. We tested these topics, along with many others, with visitors, the general public, museum members, and other museums around the country but those were the ones that rose to the top. It helped that the frozen baby mammoth, Luyba, had recently been found in Russia.”

“The whole process took about 3 years, I’d say,” she continued. “And as a whole, probably involved 60+ people to identify and conserve the specimens, develop the content with curators, design the exhibitry and graphics, source and license ages, build interactives, create videos, and build the show.”

“We did a lot of visitor studies and market research before we created [it]. I can’t say that we’ve received any feedback that startled us. It’s been very well received. In fact, the Times gave it 5 stars. That was wonderful.”

The exhibit has been seen from places as far as Chicago to Anchorage, from Boston to San Diego, but recently, from Edinburgh to the relatively nearby London.

When asked if the two recent locations in the UK were a coincidence, Hilary wrote, “We booked these two venues about 3 years ago. We were deliberate in finding 2 consecutive venues in the UK so they could share shipping expenses, which can be significant for an exhibition of this size. These two museums have worked together in the past so it was a smooth transition from one venue to the next. We book our exhibitions about 2 or 3 years out, though there are some exceptions.”

The exhibit has not changed since its inception. But, she wrote, “[s]ome venues have added graphics or specimens for their presentation, if it pertained to their own programming and collections.”

As an example, she added, “The Denver Museum of Nature and Science added a whole section about their Snowmass excavation site. But that didn’t continue on with the tour.”

Which makes the Natural History Museum an exciting place for this exhibit to temporarily reside. Proboscidean experts, Dr. Victoria Herridge and the aforementioned Professor Adrian Lister, are employed there and gave talks about their research. They have, in fact, resurrected the work of Dorothea Bate—an inspiring fossil hunter of the early 1900’s who discovered dwarf mammoth fossils in Crete—and have shed new light on her work.

NHM-DrHerridgeLyuba

[image of Lyuba and Dr. Victoria Herridge, courtesy of Natural History Museum, London]

“Other researchers must have visited the collections to look at the fossils,” Dr. Herridge explained, referring to the fossils Bate brought back to the museum, “but to the best of our knowledge we are the first to have published a taxonomic study based on the fossils themselves (rather than simply referring to Bate’s own papers or Osborn’s Proboscidea). This probably reflects the resurgence of interest in island dwarfing as a research topic in recent years.”

Dwarf mammoths—smaller versions of larger species, as their name implies—have also been referred to as ‘pygmy’ mammoths.

Is there a difference?

Dr. Herridge wrote, “The terms are used synonymously for the most part. I prefer to use ‘dwarf’ for island dwarf hippos because it helps to differentiate them from the extant hippo species Choeropsis liberiensis which has the common name ‘pygmy hippo’ — this species is not the same as the island dwarf hippos, and did not evolve to be small because of an island environment, and using dwarf helps to avoid confusion on this subject. Similarly, there is a cryptozoological belief in the existence of a ‘pygmy elephant’ in the jungle of West Africa, and using ‘dwarf elephant’ for small island elephants helps to avoid confusion here too. And to be consistent, I then also use dwarf for the small island mammoths and deer as well.”

Information on the Museum’s website indicates more work needs to be done.  It was explained that “[c]urrently there are no dates whatsoever associated with the Cretan mammoth fossils, and only a small number of dates for fossils on Crete in general. With colleagues from U. Bristol, U. Oxford and UCLA, Dr. Herridge and Professor Lister are currently working on a project to date many of the sites that Dorothea Bate excavated on Crete, including the dwarf mammoth locality. They have relocated the sites, and then taken samples for uranium series and optically stimulated luminescence dating. No new excavations for fossils have been carried out as yet, but if the results prove interesting more may be done in the future.”

NHM-ColumbianMammothSkull

[image of Columbian mammoth skull and tusks, courtesy of Natural History Museum, London]

 

“The exhibition will allow visitors to enter the amazing world of some of the largest creatures to have ever walked the earth,” concluded Professor Lister. “[Mammoths: Ice Age Giants] will take visitors on a journey from the time when these titans roamed the land through to today’s research into the causes of mammoth extinction, using new scientific research from the Natural History Museum.”

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Watch a video of the exhibit! Mammoths: Ice Age Giants – “It’s not just the bones!” | Natural History Museum

More information from Dr. Victoria Herridge about dwarf mammoths! Identification of the world’s smallest mini mammoth | Natural History Museum

And learn about the possible causes of mammoth extinction from Dr. Adrian Lister! The Last of the Mammoths | Natural History Museum

Visit the Natural History Museum in London before 7 September 2014 to see this fascinating exhibit! http://www.nhm.ac.uk/visit-us/whats-on/temporary-exhibitions/mammoths-ice-age-giants/

Watch Waking the Baby Mammoth from National Geographic (written by Adrienne Ciuffo) to learn more about Lyuba’s discovery: http://www.natgeotv.com/asia/waking-the-baby-mammoth/videos/waking-the-baby-mammoth

Order a copy of Mammoths and Mastodons of the Ice Age by Professor Adrian Lister for more fascinating details about proboscidea: http://www.fireflybooks.com/bookdetail&ean=9781770853157

Dr. Victoria Herridge will have a new book published in 2015, The World’s Smallest Mammoth: http://bloomsburywildlife.com/victoria-herridge/

Extreme insular dwarfism evolved in a mammoth: Paper written by Dr. Herridge and Professor Lister, their research of dwarf mammoths on Crete, initiated by Dorothea Bate in the early 1900’s

A Mammuthus meridionalis-sized THANK YOU to Dr. Victoria Herridge, Professor Lister, Hilary Hansen and Helen Smith for their time, their help and their generous responses to my questions! What a great honor and a true pleasure!!