Pygmy and dwarf sperm whales – hook-toothed hunters of the abyss

The pygmy sperm whales and dwarf sperm whales are remarkable for a lot of reasons, for example for their extraordinary ability to release a dark substance from a gut pouch and hide within a cloud of their intestinal fluids. Not that long ago I have already covered and illustrated this bizarre behavior. But there is so much more to say about kogiids. I think it´s fair to say that they are among the weirdest extant whales. Today there are only two remaining species, the pygmy sperm whale Kogia breviceps and the dwarf sperm whale Kogia simus.

Pygmy spem whale (Kogia breviceps) hunting a deep sea squid of the genus Taonius. Illustration by Markus Bühler

Their next living relative is the much more famous sperm whale Physeter macrocephalus. Physeter and Kogia share a number of anatomical and behavioral characters, like the prominent spermaceti organs which even extends their upper jaws. But there is a big difference. In Physeter the blowhole is located on the left side of the „nose“, close to the most anterior part of the giant spermaceti organ. In kogiids however the blowhole is still at the same position as in all other odontocetes, in the area above the eyes. It has only a very subtle and hardly recognizable lateral asymmetrical position and forms also no pronounced hump as the blowhole of Physeter. They also lack the weird array of multiple „humps“ which we find instead of a real dorsal fin in Physeter. The same applies to the lateral skin wrinkles of Physeter.

All in all the postcranial external anatomy of kogiids is as usual as possible. But at least their heads are absolutely weird. Their skulls are highly shortened and asymmetrical, with a big cranial basin for the anteriorly protruding spermaceti organ.

Their mouths are also highly unusual. The jaws are rather short and the opening of the mouth very small, nearly like an oval hole in the downside of the head. The mandibular teeth however are very long, thin and curved to the midline of the lower jaw. As a result of this weird tooth arrangement it seems that adult pygmy and dwarf sperm whales can’t fully close their mouths anymore, so they stand constantly partially open. In contrast to Physeter we find still erupted and functional upper teeth, but they are much lesser numerous and smaller in size than the mandibular teeth.

Pygmy sperm whale jaw (erroneously labeled as dolphin jaw) from the Oceania exhibition of the Museum fü Völkerkunde (Ethnological Museum) Berlin. Photo by Markus Bühler

The combination of short jaws and a small opening of the mouth with very long thin teeth is quite unusual. In general we see the opposite condition, like comparably short jaws with small, blunt or missing teeth or elongated and narrow jaws with thin and long teeth. In contrast to Physeter we see also usually no battle scars from intraspecific fights so we can be quite sure that the bizarre comb-like teeth evolved for hunting and not fighting.

Pygmy sperm whale jaw (erroneously labeled as dolphin jaw) from the Oceania exhibition of the Museum für Völkerkund (Ethnological Museum) Berlin. In this dorsal view you can ee the strong inwards curvature of the long thorn-like teeth. Photo by Markus Bühler

Pygmy and dwarf sperm whales feed mainly on small prey species which they usually hunt in depth of about 250-1.500 m. K. breviceps feeds mainly on small cephalopods whereas K. simus includes a bigger part of fish in its diet. Furthermore they also consume crustaceans like free swimming deep sea shrimps. I wanted to illustrate a hunting dwarf sperm whale in the deep sea, so I shamelessly reused my „pooping“ Kogia breviceps which I made for the blog article about the totally weird anti-predator behavior of kogiids. I had to paint much of the tail-part which was mainly blurred in the original illustration and without any detailing.

As prey species I chose a deep sea squid of the genus Taonius, which is known from the stomach contents of Kogia breviceps. This was a good chance to illustrate this rarely depicted cephalopod. This translucent squids show a very strong ontogenetic change with juveniles that have bizarre stalked eyes. The adults have highly reduced arms and still extremely bulging eyes. I also added a small swarm of hatchet fish for a bit more faunal diversity and to include a touch of bioluminescence.

But I also wanted another illustration which gives a better look on the incredible teeth of a pygmy sperm whale. Admittedly, I wanted to make it look a bit more intimidating for a more impressive effect, so I also added a reflection of the eye. In fact that´s how it can look like if marine mammals are illuminated by spotlights and filmed or photographed in dark water, so it´s not really that much imagination behind this. I used a screenshot from some deep sea footage of a sperm whale as main reference for the lights here.

Pygmy sperm whale (Kogia breviceps) snachting the giant mysid Neognathophausia ingens. Illustration by Markus Bühler

I didn´t want just another cephalopod as prey item in this case, so I decided to illustrate a somewhat lesser common species from the known diet of Kogia breviceps. It´s Gnathophausia ingens, a species of lophogastrid crustacean. This bright-red mysids grow to pretty large sizes (up to about 35 cm) and inhabit depths of around 900-1,400 m. Crustaceans are not very common in the diets of cetaceans, but they can contribute a considerable (at least up to 15%) part to the diet of pygmy and dwarf sperm whales.

Not that long ago, there was also a case in which the considerably rotten corpse of a dwarf or pygmy sperm whale was found on the beach of a Philippine island Surigaro del Norte and lead to a lot of (nearly universally erronous) speculation about its identity. The paticularly weird cranial anatomy was surely one of the main reasons why so many people did not realize that this were in fact the remains of a cetacean, and not of a seal or seacow. I covered the case here.

References:

Beatson, E. (2007). The diet of pygmy sperm whales, Kogia breviceps, stranded in New Zealand: implications for conservation. Reviews in Fish Biology and Fisheries, 17(2–3), 295–303. https://doi.org/10.1007/s11160-007-9039-9

Staudinger, M. D., McAlarney, R. J., McLellan, W. A. & Ann Pabst, D. (2013). Foraging ecology and niche overlap in pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales from waters of the U.S. mid-Atlantic coast. Marine Mammal Science, 30(2), 626–655. https://doi.org/10.1007/s11160-007-9039-9

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A possible new beaked whale species observed off Mexico

Yesterday it was announnced that some possibly hitherto unknown beaked whales were observed and photographed in the waters north of the San Benito Islands in the Pacific Ocean.

Illustration of the possible new beaked whale from the Pacific Oceans near the San Benito Archipelago

Scientists of the Sea Sheperd vessel Martin Sheen were able to observe the whales both on the surface and underwater near the archipelago of the San Benito Islands. Those three remote islands are located off Baja California, Mexico.

I tried to illustrate the species as good as possible based on the few published photos. Sadly the head was not very well visible. The presence of many large scars indicate however that the males of this species possess battle teeth. As they were howeve fully invisible this the photos and because they are among the most important diagnostic characters of beaked whales, I did not depict them here, to avoid too much speculation about their shape and position.

The beaked whales also differed acoustically from the known echolocation sounds of other beaked whales and it is expected to represent a new and yet undescribed species. Beaked whales are still among the least known cetaceans, and the biology of many species is still mainly unknown. Even new species has been described in recent years, and there is valid reason to assume that other species awaits discovery.

Of course it is problematic to identify a new animal species from observations alone, without any physical remains to work with. But this is a start for more research, and perhaps future expeditions will enable us to get more photos and echolocation data, observation of behavior and hopeyfully – DNA samples which would settle wether or not this is a fully new species or perhaps just a known species or possibly yet unknown subspecies.

Original story and photos of the mysterious whales

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Curiosity of the Day: A Native American bag made from a pelican head

Today´s Curiosity of the Day is a very remarkable bag made from a pelican head. It is on display in the exhibition about First Nations in the Canadian Museum of History, Ottawa. Sadly the only available information was that it dates to around 1900 and was made by members of the T´suu T´ina (also known as Sarcee).

T´suu T’ina pelican head bag, Canadian Museum of History, Ottawa. Photo by Markus Bühler

The head belongs to an American white pelican (Pelecanus erythrorhynchos). The skin of the head which is of yellow color was also coloured with ochre after it was tanned.

I have no idea what function this truely unusual container had, if it was just a singular curiosity or a more common thing to make bags from pelican heads for some special purpose. But in anyway it´s a fascinating object which I could not resist to share.

Veröffentlicht unter Curiosity of the Day, Ethnology, Vögel | Schreib einen Kommentar

The Nightmare Look of Naked Owls – how Feathers Conceal a Bird´s True Shape

Today I want to show you one of the coolest bird specimens I have ever seen in a museum, a bodycast of a barn owl (Tyto alba) with removed feathers. This gives us a great opportunity to see the enormous amount of volume which is made up by the feathers of a bird. It shows also very well how much the external appearance of an owl differs from the actual body below.

Bodycast of a barn owl with removed feathers, Museum Mensch und Natur, Freiburg. Photo by Marku Bühler

This is of course a particularly extreme example as owls have especially voluminous feathers on their heads and necks, what makes the difference even more remarkable.We are often used to think that feathers and fur are only thin coats that closely follow the underlying body shapes.

Bodycast of a barn owl with removed feathers, Museum Mensch und Natur, Freiburg. Photo by Marku Bühler

But in many cases we see a massive difference between the apparent body proportions with feathers or fur and the real body proportions below.The barn owl here is an excellent example for this.

Bodycast of a barn owl with removed feathers, Museum Mensch und Natur, Freiburg. Photo by Marku Bühler

It was on exhibit in a special exhibition of the Museum Mensch und Natur (museum of man and nature) in Freiburg which I visited a few years ago. I don’t think the featherless body was a real plastinated owl but quite likely a cast. We can see here all the features which are usually hidden below the thick plumage, including the weird skin folds around the ears of the owl.

Bodycast of a barn owl with removed feathers, Museum Mensch und Natur, Freiburg. Photo by Marku Bühler

Besides the featherless body was also a full taxidermy specimen for a better visualization of the differences.

Barn owl taxidermy specimen, Museum Mensch und Natur, Freiburg. Photo by Marku Bühler

A particularly good idea was also the jar filled with the removed feathers to show just how much volume they have.

Bodycast of a barn owl with removed feathers, Museum Mensch und Natur, Freiburg. Photo by Marku Bühler

Of course it’s somewhat more than the volume of the feathers as long as they are still attached to the skin. Something we also often tend to forget is the weight of feathers. They are symbols of weightlessness, and singular feathers have very little weight indeed. But altogether they summarize to a considerable weight which can make up a lot of a bird’s total weight. Reconstructions of extinct birds and of course certain lineages of feathered theropods as well (and yes, of course I am are aware that birds are technically theropod dinosaurs, yet I find it still useful to discriminate between anatomically modern birds and feathered mesozoic theropods for several reasons). We have to keep the volume in mind when we reconstruct the outlines of such animals from their bare bones, especially on body areas like the necks. The differences in the appearances can be really dramatic as even a moderate amount of feather volume can change the body shape a lot. The weight of plumage is also a considerable factor when it comes to weight estimates for extinct birds and feathered theropods as well, especially for those capable of flight which had well developed wing feathers. In the Haast´s eagle (Hiraaetus moorei) for example, the feathers of a specimen of 12,33 kg weighed around 0,85 kg alone.

Veröffentlicht unter Anatomie, Vögel | Schreib einen Kommentar

Berardius, the bus-sized deep sea predator with barnacle covered battle teeth

There is an enormous marine carnivore which grows as long as a bus, and most people are fully unaware of its very existence. Nearly everyone knows sperm whales, but if you would ask people about the world’s next largest extant predator (if we exclude baleen whales which are still carnivorous and sometimes surprisingly predatory), it’s very likely that a lot of people would struggle. Many would likely answer that orcas are the second largest carnivores, but this formidable predators are still not at the second range after sperm whales. In fact they aren’t even at the third range. I am sure that a lot of people would be very surprised to learn that there are besides sperm whales other predatory marine mammals larger than orcas in the world’s oceans. But hardly anyone could name them, and even those who know them are often not fully aware of their enormous size.

Baird´s beaked whale (Berardius bairdii) by Markus Bühler

The name of this beast is Baird’s beaked whale (Berardius bairdii), sometimes also called the giant beaked whale. This little known leviathan is an inhabitant of the northern pacific ocean, whereas its slightly smaller antarctic sister species, the Arnoux‘ beaked whale (Berardius arnuxii), inhabits the circumpolar oceans of the southern hemisphere. Giant animals gain usually a lot of attention, even more so if they are predatory. Even children’s books are full of sperm whales, baleen whales, orcas, whale sharks or basking sharks and you can see them in countless documentaries. So how could it be that Berardius somehow evaded to get attention? Beaked whales are in general quite elusive and still among the least known big mammals of the world.

Even today some species are only known from a handful of specimens and we still know nearly nothing about much of their behavior. As late as 2019 a „new“ species of Berardius was described from Japanese waters, Berardius minimus (more about earlier implications for this new species at Lord Geekington). It had been known to Japanese whalers since a long time and was called kuro-tsuchi (meaning „black Baird´s beaked whale). In contrast to B. bairdii which is greyish with some white markings in the chest area, B. minimus is nearly fully jet-black. It also differs in its body proportions from Berardius bairdii, which occurs in the same area. B. minimus has also a stouter melon, a shorter and more compact body shape and a much smaller size, growing „only“ to about 6,9 meters. It also seems to suffer more from cookie cutter sharks than Berardius bairdii, as the known specimens showed a particularly large number of bite scars from this parasitic sharks. On the other hand the overall amount of battle scars from intraspecific fights appears considerably lesser than in B. bairdii. Here is a wonderful illustration of Berardius minimus by Jaime Bran:

Berardius minumus by Jaime Bran

Battle teeth and barnacle-plaque

Most beaked whales have a highly reduced yet also highly specialized dentition. Cephalopods and smaller fish are caught by suction feeding for which teeth are not necessary, especially as most prey items are very small. The pair of lateral throat grooves and the well-developed hyoid bone and muscles can create a strong vacuum to literally suck in prey. In general only the males have teeth, usually a single pair. Beaked whales of the genus Berardius however have four remaining teeth in the lower jaw which also erupt in both sexes, whereas the upper jaw is completely toothless.

Head detail of Berardius bairdii with the extraorally located first pair of teeth.

The first pair is located at the top of the prognathic mandible and is functionally extraoral (narwhals are not the only cetaceans with such a condition, we see this also in many beaked whales) whereas the second pair of teeth remains hidden as long as the jaws are closed. Many thanks to Sally Evans who made some great photos of a Berardius arnuxii skull at the archives of the Natural history Museum in London for me.

Berardius arnuxii skull. You can see very well the how the lower jaw is longer than the upper jaw. Photo by Sally Evans

Those teeth are used during intraspecific fights and both males and females show scars from such confrontations. In some old males nearly the whole fore half of the back consists of scar tissue. Most of the scars were obviously caused by the first pair of the antagonist’s teeth, but sometimes you can also find four parallel lines of scars as well. I still wonder how exactly they manage to produce this kind of pattern. The parallel orientation of this scars means that the attacker scratched the skin either during a forward facing movement with widely open jaws or that it tried to bite the other whale and was moving backwards.

Detail of the body with various scars. Most of them are tusk scars from intraspecific fights, the round scars are cookiecutter shark scars.

The teeth in dorsal detail view.

Detail of the mandibular teeth of Berardius arnuxii. Photo by Sally Evans.

Adding scars to an animal is usually a fun part (much of the drawing and painting time is hard and exhausting work), it gives you the chance to give it some individuality and tell some stories of its life. But the amount of battle scars in Berardius is often of such an extreme extension over the body that I decided to depict it only with a very moderate amount of scars, like we see it in younger males. Too much white scar tissue makes it hard to see the original shape and anatomy of the body.

Due to the common use, the teeth they have also often strong abrasions in older individuals and can be worn down to the skin. Because those teeth are all the time surrounded by the sea, they get colonized by shell-less goose barnacles. This is a very common thing in beaked whales with extraoraly located teeth. In Berardius it’s mainly the marginal part of the teeth near the skin where the barnacles grow like a little brush. But sometimes the barnacles grow to quite considerable sizes, forming fleshy masses that look like kelp. You can see an example of excessive goose barnacle growth here.

Massive barnacle growth on the tusks of a Baird´s beaked whale. Scan from The Canadian field-naturalist (1993). Photos courtesty of H. Omura, from Leatherwood et al. (1982: 90). Source: Wikipedia

The social life of Berardius is weird to say it at least, and could well be a chapter of its own. So I´ll refer here to Cameron McCormick´s excellent blog article which also deals with this topic.

I wrote that Berardius minimus grows „only“ to about 7 meters. But how big is Berardius bairdii? The average is about 10-11 m, where males are somewhat smaller than females. The maximum recorded length for this species is 12,7 m and the maximum weight at around 10-15 tons. This is really enormous, bigger than every orca, and they range in a similar size class as the next biggest rorquals like the Bryde whale and Omura’s whale.

Dead Baird´s beaked whale at a whaling station at Japan. Scan from The Canadian field-naturalist (1993). Photos courtesty of H. Omura, from Leatherwood et al. (1982: 90). Source: Wikipedia

Arnoux´beaked whale is somewhat smaller but still reaches lengths of 9,75 m. As a result of the extreme sexual size dimorphism of Physeter the size range of Berardius even overlap with those of female sperm whales, and large Baird’s beaked whales are even longer than average-sized female sperm whales. Berardius bairdii also fills a similar ecological niche as Physeter and mainly feeds on cephalopods and fish in the deep sea. The main difference is that its diet does not include bigger prey species like large squids or sharks. But even sperm whales feed mainly on animals which’s are proportionally tiny and really large prey like adult giant squids are usually only consumed by males anyway. So it would be really interesting to know how much both species compete in areas where they are sympatric.

Here is a size comparison of a female B. bairdii with an average female sperm whale which I made during an early version of the illustration.

So far no one has ever seen Berardius hunting but it would be an incredible sight to watch those leviathans patrolling the floor of the north Pacific and sucking in half-meter long grenadiers. That’s why I tried to create an illustration of a hunting Baird’s beaked whale to give you some idea how this could look like. Right now, when you are reading this lines, something like this happens in reality, but in pure darkness. Just think about this, we life in an awesome world.

Berardius bairdii is a comparably opportunistic hunter which feeds on a large number of very different deep sea squid and fish. Grenadier fish or rat-tails make up a big part of their diet. This fish reaches usually lengths of about a 0,5-1 meter and stay usually close to the seafloor. In many areas they are among the most numerous deep sea fishes and make up much of the vertebrate biomass. Some species are even commercially fished. But Berardius also feeds on many other species, from codlings to lancetfish.

Pacific grenadiers are among the most important prey animals of B. bairdii

From examinations of stomach contents we also know various cephalopod prey species of Berardius bairdii, even small specimens of Architeuthis (the famous giant squid) were already recorded. It seems that hunting occurs mainly close to the seafloor and Berardius can dive at least to depths of 1777 meters.

Galiteuthis pacifica

I looked for various references for the sea floor and the other animals around. The small swarm of fish chased by the whale are Pacific grenadiers (Coryphaenoides acrolepis), the small translucent squid on the right a subadult specimen of Galiteuthis pacifica which is also known from stomach contents of B. bairdii. I also depicted a grey cutthroat (Synaphobranchus affinis), a deep sea eel which is also a known prey species.

Monster carcasses

The giant size, the somewhat unusual anatomy and the unfamiliarity of many people with beaked whales in general and the transformation powers of taphonomy resulted into several cases in which carcasses of Berardius bairdii were mistaken for sea monsters. One of the most famous cases, the Moore beach carcass (featured by Darren Naish at Tetrapod Zoology), is still often claimed as the alleged relics of a modern day plesiosaur. An upside down floating Berardius bairdii was assumed to be a late surviving archaeocete (also covered at Tetrapod Zoology). Another much more recent case from 2015 gained a lot of attention in the international press. The „bird-beaked“ and „hairy“ carcass which washed ashore at Sakhalin Island was assumed to be a giant hairy dolphin, a Ganges freshwater dolphin and even the relics of a mammoth from the permafrost which was somehow washed to the sea. This identifications are all highly absurd and it´s surprising that no real experts were asked for their expertise. The size, the shape of the skull and jaws, the melon and the visible flipper bones all clearly show it was a Berardius carcass, and the „hair“ is just a very common artifact of decomposition when tissue fibres disconects from each othe. Cameron McCormick wrote also about the sometimes bizarre effects of decomposition and scavenging on Berardius carcasses. I included some of those cases also in a talk which I gave in 2018 about „monster“ carcasses, in which I presented various cases of misidentified animals which were claimed to be monsters, „dinosaurs“ or other alleged prehistoric or unidentifiable beings which – according to tabloids and internet news – baffled scientists all the time. I explained how taphonomy can drastically change the appearance of an animal’s body and why cetacean carcasses in particular are so prone to get misidentified as monsters. It was especially important for me to show how you have to systematically examine such cases for the identification from anatomical traits which are usually not affected by mere degradation of soft tissue. But that’s another topic of its own which I want to cover another time.

References:

Leatherwood, S., R.R. Reeves, W.F. Perrin, and W.E. Evans, 1982. Whales, dolphins, and porpoises of the eastern North Pacific and adjacent Arctic waters, A guide to their identification, NOAA Tech. Rept., NMFS Circular 444, 245 pp.

Ohizumi, H., Isoda, T., Kishiro, T., Kato, H., 2003. Feeding habits of Baird’s beaked whale Berardius bairdii, in the western North Pacific and Sea of Okhotsk off Japan. Fisheries Sci 69, 11–20. https://doi.org/10.1046/j.1444-2906.2003.00582.x

Walker, W.A., Mead, J.G., Brownell, R.L., 2002. DIETS OF BAIRD’S BEAKED WHALES, BERARDIUS BAIRDII, IN THE SOUTHERN SEA OF OKHOTSK AND OFF THE PACIFIC COAST OF HONSHU, JAPAN. Marine Mammal Sci 18, 902–919. https://doi.org/10.1111/j.1748-7692.2002.tb01081.x

Yamada, T.K., Kitamura, S., Abe, S., Tajima, Y., Matsuda, A., Mead, J.G., Matsuishi, T.F., 2019. Description of a new species of beaked whale (Berardius) found in the North Pacific. Sci Rep 9, 12723. https://doi.org/10.1038/s41598-019-46703-w

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The feathered Warsaw Dilophosaurus

Originally I wanted to continue the series about the Messel-fossils, but I am still working on a reconstruction illustration for the next part and needed a break. Instead I´ll jump on the Dilophosaurus bandwagon, because this awesome theropod from the Early Jurassic is just big in the news, and it´s a good excuse to finally post some photos about a quite unconventional yet very cool Dilophosaurus reconstruction from the Geological Museum in Warsaw. I don´t even want to go here into the details of the new publication but mainly show you some photos which I took several years ago in Warsaw:

Dilophosaurus reconstruction in the Geological Museum Warsaw. Photo by Markus Bühler

As you can see, nearly the complete body of this reconstruction is covered in filament-like feathers, quite in contrast to the common depiction of Dilophosaurus with nothing but naked scaly skin. This is btw not the first time I wrote about this species. Years ago I already discussed why the popular idea that it was just a scavenger was not really likely.

Dilophosaurus head detail. Photo by Markus Bühler

Here´s a detail of the head. It´s not that easy to see from this direction, but the artists even added some fin bristle like feathers to the head.

Dilophosaurus in frontal view with nice bristles. The crests are rather thin, but the new research has shown the were possibly much more volumous in reality. Photo by Markus Bühler

It comes already quite close to the new (and pretty awesome-looking) reconstruction by Brian Engh. Of course this version does inclued a pretty large amount of artistic freedom regarding the soft tissue reconstruction, but it looks really very interesting. Brian´s Dilophosaurus puppet is also a wonderful example how life-like well-made models can look and how superior they still are compared with most CGI attempts. Take a look at this video by Brian, which includes also some information about the news from the paper.

The appearance of the Warsaw Dilophosaurus is even more surprising given the fact that the model was created in 1997 by Marta Szubert. At that time theropods were still nearly universally portrayed without any feathers or filaments and hardly anyone considered to depict a big theropod with anything else than scaly skin.

The featherless parts of the arms and legs of the model from Warsaw were also quite nicely sculpted, especially the scale patterns of the feet looked highly realistical (more about the scale patterns on the legs of ostrichs and emus).

There was a huge amount of information which was used to create this reconstruction, for example various body impressions.

Here is another photo in full lateral view. I really love how the tail was covered in alternating black and white feathers.

In 2013 Darren Naish already wrote another blog article with some additional background information about the history of this particular reconstruction. I highly recommand to read it.

If you ever visit Warsaw, you should really take some time and visit the Geological Museum. Its paleontological section is not quite big, as it mainyl focuses on geology and mineralogy, but it´s still really worth to visit. If you want to see more fossils, including the likely best exhibition about Tarboaurus, you have to visit the Museum of Evolution, which is located in the monumental Palace of Culture.

Veröffentlicht unter Dinosaurier | 3 Kommentare

Fossil treasures of Messel Pit part II: Crocs and gators

The fauna of the area which would later become the Messel pit was quite rich in crocs. Some of them strongly resembled modern crocodylians, but some of them were oddballs which differed strongly from any extant species.

The big reptile showcase of the Messel exhibition in the Senckenberg Museum at Frankfurt

The biggest crocodylian of Messsel was Asiatosuchus germanicus, a species which is known from skulls (including the mandible length) up to about 68 cm in length. The total length was up to about 3,5-4 m, about the size of an average American alligator. The very broad and robust jaws also resemble those of an alligator, and it is likely that Asiatosuchus had a similar ecology.

Asiatosuchus germanicus skull, Senckenberg Museum Frankfurt

Asiatosuchus was also the largest animal found in the Messel pit and also the largest carnivore. In contrast to most of the fossils from the lake sediments which had to be transfered from the surounding matrix into an expoy-layer during a complex process, some of the larger croc fossils were massive enough to prep the bones completely out of the oil-shale.

Asiatosuchus germanicus skull, Senckenberg Museum Frankfurt

Here is the partially preserved postcranial skeleton:

Asiatosuchus germanicus hindquarters, Senckenberg Museum Frankfurt

The other Messel crocs were considerably smaller. Diplocynodon darwini for example, an alligatoroid, reached only lengths of about 1,5 m.

Diplocynodon darwini fossil, Senckenberg Museum Frankfurt

This species is knwon from many very well preserved skeletons.

Diplocynodon darwini fossils, Senckenberg Museum Frankfurt

Even tiny hatchlings were preserved.

Juvenile Diplocynodon fossil, Senckenberg Museum Frankfurt

Another small diplocynodontine crocodylians was Diplocynodon deponiaa (formerly Baryphracta deponia). Sadly the only photo I took was rather bad in quality, but at least you can still see one of the most noticeable traits of this species, its very well developed osteoderms:

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Diplocynodon deponiae fossil, Senckenberg Museum Frankfurt

Those crocodylians were all comparably similar to some of our modern species. But there were also very distinct forms which have no ecological equivapents today. One of them was the alligatorine Hassiacosuchus haupti (formerly Allognathosuchus haupti). This was a also a rather small animal which only grew to about 1,5 m. It had an extremely shortend snout and wide blunt mushroom-shaped teeth in the posterior part of its jaws. This indicates a certain specialization for small hard prey animals like snails, crabs or small turtles.

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Hassiacosuchus haupti fossil

The coolest Messel-croc is sadly only known from very fragmentary remains, a partial mandible and a partial skull (which was sadly not on exhibit) of a single specimen found in the shales. It was Bergisuchus dietrichbergi, a small sebecosuchian. This lineage of crocodyliforms is especially well known from South America, where they evolved a big diversity with some particularly large species. This animals were totally unlike any modern crocodylians and resembled to some degree the large predatory archosaurs from the Triassic like Batrachotomus. They were fully terrestrial and agile and long-legged hunters. Their deep jaws had laterally flattened teeth with sharp serrated edges like those of theropod dinosaurs, but with a pair of enlarge canine-like teeth in the mandible. This animals are very little known and hardly ever mentioned even in paleontology books, but for millions of years those animals were among the dominant terrestrial predators in many parts of the world.

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Cast of partial mandible of Bergisuchus dietrichbergi

Bergisuchus was not even the only terrestrial croc of Messel. Another species, originally described as Pristichampsus rollinanti but now dedicated to Boverisuchus is also known from this site, sadly only from extremely fragmentary remains, without any specimens in the exhibition. Here is a speed painting by Joschua Knüppe of Boverisuchus.

Boverisuchus by Joschua Knüppe

This animals had lesser deep jaws than the sebecosuchuians but shared with them the ziphodont meat-slicing dentition. Boverisuchus reached lengths of up to 3 m, but to the usually rather small mammals of the Messel-fauna they must have appeared like huge monsters.

In the next part I will cover the other reptiles from the exhibition.

Veröffentlicht unter Amphibien, Krokodile/Crocodylians, Museen, Paläontologie, Reptilien | Schreib einen Kommentar

Fossil treasures of Messel pit part I: Fish

The Messel pit is one of the most spectacular fossil sites of the world. It gives us an incredible insight into a subtropical ecosystem from the Eocene, about 47 million years ago. The special conditions of this Lagerstätte did not only preserve the bones of the animals which lived in and around a deep crater lake, but also in some cases hair, feathers and body silhouettes, even insects with their colors still preserved. It enables us to get a vivid view of a bygone world, from its plants to insects, fish, amphibians, reptiles, birds and mammals.

It was a weird world which consisted of the survivors of the mass extinction at the end of the Cretaceous 66 million years ago and lineages which had just started to evolve into many animals which we know today. We find a lot of animals which appear surprisingly familiar and modern to us, yet considerably out-of-place in many cases, but also weird archaic lineages and overturned experiments of evolution. In this series I want to feature some of the fossils at the Messel pit exhibition of the Senckenberg Museum at Frankfurt, which I visited in early spring, just before the country was hit by the pandemic. I don´t want to go too much into the details of the species, as this would easily go beyond the scope of this blog article.

I will start the series with the fishes from the exhibition. The most famous fish from Messel pit are quite likely the gars, which I featured already in an earlier blog article several years ago. Today we find gars only in the New World, mainly in the east of the United states, at Cuba and parts of Mesoamerica. But 47 millions years ago gars did swim also in the area which would later become Germany. Gars have interlocking ganoid scales with a very hard layer of enamal on the surface and often fossilize particularly well. The most common species of gar from Messel was Atractosteus strausi (Syn.: A straussi, A. straußi, M. messelensis and A. kinkelini):

Atractosteus strausi, Senckenberg Museum Frankfurt, photo by Markus Bühler

This is a quite common fossil of Messel pit, and you can find similar specimens in many museums around the world. It looked quite similar to modern gars, but remained much smaller than any of the extant species, usually only 20-30 cm on average and about 40 cm at maximum. This is really tiny compared to the giant alligator gar which can reach record lengths of about 3 m. Gars are quite archaic fish which differ from most other extant bony fish in a number of anatomical traits, like their ganoid scales or the heterocercal caudal fins.

Atractosteus strausi, Senckenberg Museum Frankfurt, photo by Markus Bühler

Here is another fossil, fully prepped out of the surrounding matrix:

Atractosteus strausi, Senckenberg Museum Frankfurt, photo by Markus Bühler

Besides A. strausi we find also another small, yet considerably weirder gar, Masillosteus kelleri. It was somewhat bigger than A. strausi and differed from all extant gars in its short and robust jaws which were not adapted to feed on fish but to crush hard-shelled invertebrates with its big and flattened teeth. Sadly there were no fossils of this species on display, but you can see a great life reconstruction of A. strausi and M. kelleri by Joschua Knüppe here:

Fossil gars of Messel pit by Joschua Knüppe

Besides the gars was also another primeval predator, the amiid Cyclurus keheri:

Cyclurus keheri fossil, Senckenberg Museum, Frankfurt. Photo by Markus Bühler

Amiids are a very ancient lineage of bony fish and are not very closely related with any other modern fish. Like the gars they have a heterocercal caudal fin. It was the large fish of this waters and large specimens reached lengths of around 70 cm.

Cyclurus keheri fossil, Senckenberg Museum, Frankfurt. Photo by Markus Bühler

In the Mesozioc there was a huge diversty of amiids, but today there is only one single remaining species, the bowfin (Amia calva) which is restricted to the North American continent. Besides its unusual caudal fin it doesn´t really look particular primitive, but it´s nearly some kind of freshwater analogue of the famous coelacanths of the genus Latimeria. Cyclurus keheri was quite similar to the modern bowfin in appearance, perhaps a little bit stockier. Here is a photo of a modern member of Amia calva by Arthur Kosakowski for comparison:

Modern bowfin (Amia calva), photo by Arthur Kosakowski

Take a close look at the fossil and its well developed teeth, which are very similar to those of the modern bowfin. They aren´t visible in the living fish, because they are hidden by the fleshy lips. Without living relatives for comparisons, we would quite likely only see quite toothy life reconstructions of it. Here is also another nice photo of a juvenile bowfin by Kurtis Smith:

Juvenile bowfin (Amia calva), photo by Kurtis Smith

We know similarly sized specimens from C. keheri from Messel, and tiny gars as well:

Fossil eel, juvenile bowfin, Thaumaturus intermedius and juvenile gars. Senckenberg Museum, Frankfurt. Photo by Markus Bühler

The small fish below the bowfin is Thamaturus intermedius. Its taxonomical relations are still somewhat problematic, some of the sources I found say it was related with mooneyes, whereas other sources say it was a member of the Salmoniformes. There are only two remaining species of mooneyes today, which also live solely on the North American continent today, but have a good fossil record from other continents as well. Despite their unremarkable appearance they belong to a quite archaic lineage and have some quite interesting relationships with the Osteoglossiformes which include such remarkable species like arapaimas or arowanas.

On the left you can see a fossil of the eel Anguila ignota, which is the rarest of all fishes from Messel pit, known only from a single specimen.

The ichthyofauna of Messel pit is quite low in species number and appears surprisingly unexotic, unlike the oddballs which we find among the rest of the contemporary fauna (more about them in the next parts of the series). What I find really interesting is that it includes so many lineages which are now restricted the New World, North America in particular.

Another predator was Amphiperca multiformis, a small but particularly large-headed and big-mouthed perch with a deep body, which looked a bit like a small and shortened version of a warmouth (Lepomis gulosus).

Fossils of Amphiperca multiformis, Senckenberg Museum, Frankfurt. Photo by Markus Bühler

I made a simple speed-painting based on a skeletal drawing of Amphiperca. I usually spend much more time to make fine details and such things, but this time I really only wanted a quick illustration which was done in little more than an hour. I used some color morphs of the highly variable warmouth as main color reference. The fins of this fish are folded, because it´s directly based on the fossil of a dead fish. When the fish was still alive they were of course flexed and looked slightly different, but I wanted to stay as close as possible to the actual proportions of the fossil, so I didn´t try to reconstruct them in a different shape.

Speed-painting reconstruction of Amphiperca multiformis by Markus Bühler

There is also another small perch known from Messel pit, Palaeoperca proxima, whose fossils are however not as common as those of Amphiperca. It was about 20 cm in total length and had a more elongated body than Amphiperca and the two dorsal fins were distinctly separated. Its proportionally much smaller mouth indicats that it also mainly feed on comparably small prey. Sadly there were no fossils of this species on display. The next part of the Messel pit series will cover the reptiles.

Veröffentlicht unter Evolution, Fische, Paläontologie | Schreib einen Kommentar

Shit happens part IX: The fatal snake hunger of a grebe

Bizarre deaths and accidents of animals were already covered for several times on the blog, especially in the shit happens-series. Today I want to feature an interesting specimen to continue this topic. This is a partially dissected great crested grebe (Podiceps crestatus) which was found dead, after it tried to gobble an adult European grass snake (Natrix natrix).

Great crested grebe which suffocated while trying to swallow a European grass snake. From the collection of the Senckerberg Museum at Frankfurt. Photo by Markus Bühler

I appears that the snake´s body somehow formed a knot around the grebe´s lower jaw, with fatal effects for both opponents. Great crested grebes usually prefer much smaller prey items like small fish in the range of 10-15 cm, sometimes also amphibians and invertebrates. The normal maximum length of their prey is about 25 cm, so this grebe was particularly enthusiastic when it trid to swallow a whole grass snake which likely exceeded its own body length. You can even see the snake´s head in the opened stomach:

Head of the grass snake in the opened stomach cavity of the grebe

The snake inside the grebe

To give you a better idea of the size of the snake inside, I´ve tried to make a simple reconstruction of it. I have to emphasize this is really just a speculative reconstruction, without an X-ray image it´s hard to say how exactly the snake was curled inside the stomach and perhaps the curve I expected for the snake´s body inside the grebe´s esophagus was not curved enough. But anyway, here it is:

Reconstructed grass snake inside the grebe

The tragic death of the grebe and the snake aside, we see here also an interesting example how unpredictable animal behavior can be. Who would have expected that a grebe would try to attack a snake which is several times as long as its usual maximum prey size for example?

The dissected grebe sadly doesn´t really show the beauty of this elegant kind of waterfowl, so I wanted to finish this blog entry with a somewhat lesser macabre photo. I see grebes comparably often in the wild, but they are usually too shy and too far away to take good photos of them. But several years ago I managed to take some better close-up photos of some grebes at Lake Garda.

Great crested grebe, Lake Garda. Photo by Markus Bühler
Veröffentlicht unter Reptilien, shit happens, Vögel | Schreib einen Kommentar

The rasping Mouth of Death

I haven´t posted new stuff on the blog since quite some time, but not because I´m no more writing, but due to the amount of work which is going into some future blog articles. For that reason I was looking for something interesting I could post until the next bigger article is finished. I found a really interesting photo of the mouth of a sea lamprey (Petromyzon marinus) from the Zoological Museum at Kiel at my archive. It looks so wonderfully monstrous yet disturbingly aesthetic for its sheer obvious efficiency that I just had to share this:

Mouth of a sea lamprey (Petromyzon marinus), Zoological Museum Kiel

Sea lampreys are the largest lampreys and can reach lengths of over 1 meter, but usually stay within the range of 70-90 cm. The adult sea lampreys make living as parasites of larger fish, which they attack with their sucker-like mouths and keratinous pseudoteeth and tongue. They rasp and cut pieces out of the fish´s skin until they reach the underlying tissue, so they can suck the effluenting blood, lymph and shreds of tissue.

They became especially infamous after they invaded the Great Lakes and caused havoc among the populations of local fish like lake trouts (Salvelinus namaycush). Here is a taxidermy cast of a namaycush with an attached sea lamprey from Redpath Museum, Montreal:

Sea lamprey attacking a lake trout, Redpath Museum, Montreal.
Veröffentlicht unter Fische | 2 Kommentare