Friday Fossil Feature – It would be Folly to pass this site up

By Robert Boessenecker (@CoastalPaleo) and Sarah Boessenecker (@tetrameryx)

 

Photo by R. Boessenecker

Folly Beach is a popular destination near us here in Charleston, and thousands of swimmers, sun tanners, and surfers flock to the beach during the summer and relatively warm spring and fall months; the water is a few degrees warmer than Hawaii, and we will on occasion leave work early every couple of weeks to go swimming. Folly started out as a bit of an artist’s village, and is where George Gershwin wrote the opera “Porgy and Bess” about life in Charleston. Folly Beach is a barrier island, separated from Charleston Harbor to the northeast only by the relatively small Morris Island – the location of Battery Wagner. Battery Wagner was a Confederate artillery battery guarding Charleston Harbor, assaulted in 1863 by Union troops including the 54th Massachusetts Volunteer Infantry – one of the first African American units in the Union Army – and depicted in the 1989 film “Glory”. Hurricanes occasionally uncover Civil War era artifacts, and after Hurricane Matthew last fall, beach walkers found an uncovered store of cannon balls – unclear if solid “round shot” or mortar shells filled with black powder – which, regardless, were detonated by a bomb squad.

Tropical Storm Hermine and Hurricane Matthew uncovered quite a bit of older material this last fall, chiefly fossils and limestone blocks dating to the last 30 million years. A variety of fossils can be found on the beach at Folly, and while not as plentiful as at Edisto Beach, Folly is much closer to us. We’ve gone several times recently, and collected many pounds of fossils. One major scientific issue with collecting fossils from Folly is that the source of the specimens is inconclusively known – and any consideration of the stratigraphic (i.e. geologic) source of the fossils is speculative. Fossils occur isolated on the beach, and except in rare cases, vertebrate fossils do not have any adhering rock. No fossiliferous exposures crop out at Folly, and fossils come from two different sources: 1) natural submarine exposures just offshore and within rivers, washed back onto the beach and 2) sediment delivered by beach renourishment. Folly Beach has been eroding away, and within living memory the width of beach and dunes has decreased noticeably, with hurricanes like Hugo (1989) contributing; other factors include the construction of the Charleston harbor jetties, which prevent sediment from Sullivan’s Island being transported south to Morris and Folly. Sediment for renourishment is either dredged or piped up from “borrow” areas – some of which are in river mouths, but most is from about 3 miles offshore. Renourishment in 2015 from the offshore borrow area introduced a large number of limestone nodules, which have been the source of much ire and complaining from Folly residents, but possibly a boon for geologists.

We still don’t have a great idea of what strata are exposed in these areas, and several problems plague stratigraphy in the Charleston embayment: 1) Exposures are rare and many deposits are known only in the subsurface, either from well cores or seismic data; 2) many deposits, according to seismic data, are not laterally extensive and taper out over a few miles – making mapping and correlation a bit of a nightmare. We’ll be using the stratigraphic framework from the geologic map of the area published recently by USGS stratigrapher and paleontologist Rob Weems and others (2014). But before we get there, what fossils can you find?

Photo by R. Boessenecker

Hemipristis serra, the snaggle tooth shark. Photo by R. Boessenecker

Photo by R. Boessenecker

Most visitors come for the shark teeth – and shark teeth can be found. They are perhaps not as common at Folly as at other beaches in the southeastern USA, but I’ve walked away with a dozen after only a couple hours of searching. Common shark teeth include Sand tigers (Odontaspis, Carcharias; Oligocene-Recent), and reef and lemon sharks (Carcharhinus, Negaprion; Eocene-Recent). These all have long stratigraphic ranges, and are notoriously difficult to identify – and could come from any of the Oligocene through Pleistocene strata in the Charleston area. Some of the rarer, larger, and more highly sought after teeth including great white sharks (Carcharodon carcharias, Pliocene-Recent), “bigtooth makos” (Carcharodon hastalis, early-late Miocene), and the megatoothed sharks (Carcharocles megalodon, early middle Miocene to early Pliocene; Carcharocles angustidens, Oligocene), tiger sharks (Galeocerdo, Physogaleus spp.), and snaggletooth sharks (Hemipristis serra, Eocene-Pleistocene) are somewhat better age indicators. Confusingly, all of these occur at Folly Beach – indicating that Oligocene, Miocene, and Pliocene rocks all occur nearby or in the borrow areas. Other sharks including bat rays also occur, and shark/ray vertebrae are also known.

Photo by R. Boessenecker

Fossils of bony fish are common, but typically left behind. Common examples include beaks of the pufferfish Chilomycterus schoepfi (early Miocene to Recent), partial skulls of sea robins (Prionotus sp., Pliocene-Recent), partial skulls of bonitos (Sarda sp.; Eocene-Recent), and osteoderms of a sturgeon (Acipenser sp., Cretaceous to Recent). Fish bones are a bit of a nightmare for paleontologists, since fish have such a high number of bones that typically disarticulate, and comparable parts are rarely found. At Folly, mostly well-preserved, dense elements resistant to destruction are found, meaning that it is relatively easy to find consistently occurring specimens of the same morphology. Unfortunately, we have no record of the more delicately built fishes.

Photo by R. Boessenecker

Reptile fossils are in abundance, unlike equivalent deposits on the west coast. Turtle shell elements are actually quite common, and readily identifiable – for someone who knows about turtles. Shell identification of turtles has always seemed like a black art, but we’ve got quite a few now. Specimens obvious enough for chelonian novices like us include large tortoises (Geochelone, Eocene-Recent, or Hesperotestudo, Miocene-Recent), some sort of a large softshell turtle (Trionychidae indet., Cretaceous-Recent), and pond turtles (Emydidae, Cretaceous-Recent). Our collection includes a large, somewhat flat leg spur of a large tortoise. Sea turtles should be encountered, but it’s unclear if our preliminary searches have uncovered any; a single possible osteoderm of a leatherback sea turtle (Dermochelyidae indet., Eocene-Recent) was collected just a few days ago. Crocodilian remains are comparably rare, and we recently collected a partial osteoderm (scute) of extant Alligator (Eocene-Recent).

Photo by R. Boessenecker

Mammalian bones are the most commonly encountered fossils, and these are almost always left behind. These are fragments of much larger bones – by volume, most I assume are from whales (ribs, mandibles). On occasion highly dense bone fragments likely represent pieces of sea cow (Sirenian) ribs. It is worth picking up each one and checking it over to make sure it’s not an identifiable specimen before chucking it back into the sand.

Photo by R. Boessenecker

Land mammal remains are quite common, and include shards of thin-walled bones with a large marrow cavity (clearly not marine mammals), teeth, and tooth fragments. Horse teeth and fragments thereof are perhaps the most common (Equus sp., Pliocene-Recent), and fragments of teeth and tusks of American mastodon (Mammut americanum, Pliocene-Recent) and woolly mammoths (Mammuthus spp., Pleistoecne-Recent). Tusk fragments of the latter can be identified based on distinctive cross-hatching in cross-section. Teeth of artiodactyls are less common (e.g. Bison, Pleistocene-Recent). Our growing collection also includes remains of edentates – including osteoderms of the giant armadillo Holmesina.

Photo by R. Boessenecker

Occasionally identifiable specimens of whales and dolphins (Cetacea) are found. Marine mammals are more difficult to identify than terrestrial mammals, as teeth are either completely absent (baleen whales) or the teeth are similar between species (toothed whales). Earbones are quite important instead, and two different types of earbones may be found – the periotic and the tympanic bulla. Each look quite strange, but if complete enough, are identifiable to the family, genus, and occasionally species level. One recent find by us includes a partial periotic of baleen whale similar to Parietobalaena from the early-middle Miocene Calvert Formation of Maryland. Another specimen, recently donated by Edisto State Beach Ranger Ashby Gale, is a periotic of a pygmy sperm whale (Kogiidae indet.), an unnamed species that is so far known only from periotics from the Pliocene of North Carolina and Florida. The specimen is not photographed here because it is currently being molded and casted.

Photo by R. Boessenecker

For every genuine vertebrate tooth or bone on the beach, there are about a thousand shells and a handful of black phosphate pebbles. Phosphate is a type of sedimentary “nodule” or concretion formed during periods of low sea level with slowed deposition. Slow deposition also favors the formation of vertebrate rich bonebeds – when phosphate pebbles are present in an area, they are usually concentrated and formed under the same conditions that characterize the concentration of vertebrate fossils into bonebeds. Simply put, if black phosphate pebbles are common, look for bones and teeth! Also keep your eyes peeled for coprolites – fossilized poop. Phosphate pebbles which look like poop are very likely to be just that. Coprolites, bones, and teeth are all phosphatic, and share the same chemistry with phosphate pebbles.

So, we know that there are fossils from the Oligocene, sometime in the early-middle Miocene, the Pliocene, and the Pleistocene from Folly Beach – all mixed together, naturally and by beach renourishment. The geologic map of Charleston published by Rob Weems includes deposits of the lower Oligocene Ashley Formation, the lower Miocene Marks Head Formation, the Pliocene Goose Creek Formation, and the upper Pleistocene Wando Formation. We think that these strata are the likely sources of the fossils from Folly Beach, with the terrestrial reptiles and land mammals all originating from the Pleistocene Wando Formation.

We need your help! The vertebrate fossils of Folly Beach have never been published before in a scientific paper. We are currently seeking donations of vertebrate fossils from Folly Beach to help “fill out” the fossil assemblage in our collection in order to permit scientific study of the locality. If you have found some of the more uncommon fossils – in particular, whale or dolphin earbones or mammal teeth – we encourage you to consider donating the specimens to CCNHM for scientific study and display in our museum!

 

Sources Cited:

Weems, R.E., Lewis, W.C., and Lemon, E.M., Jr., 2014, Surficial geologic map of the Charleston region, Berkeley, Charleston, Colleton, Dorchester, and Georgetown Counties, South Carolina: U.S. Geological Survey Open-File Report 2013–1030, 1 sheet, scale 1:100,000, http://dx.doi.org/10.3133/ofr20131030.

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Friday Fossil Feature – Fintastic surfprises from Lee Cone’s Whale

by Robert Boessenecker (@CoastalPaleo) & Sarah Boessenecker (@tetrameryx)

Happy Fossil Friday!

The more we unpacked, the more excited we got as we learned just how much was donated. Photo by S. Boessenecker

The more we unpacked, the more excited we got as we learned just how much was donated. Photo by S. Boessenecker

Two weeks ago, fossil collector Lee Cone (President of the Special Friends of the Aurora Fossil Museum) donated a spectacular skeleton of a large baleen whale (Mysticeti) from the Lee Creek Mine (read about it here). A skeleton of a mysticete like this is unprecedented as it includes a partial skull, earbones, mandibles, vertebrae, and ribs. However, it also includes a number of other fossils that decidedly do not belong to the whale – including non-cetaceans, parts of at least one or two additional mysticete whales, and at least two pygmy sperm whales (Kogiidae).

Associated fish, sea turtle, and bird remains

Several bones mixed in with the whale record the presence of sea turtles, a sea bird, a sturgeon, and a billfish. Several bones from the edge of a turtle shell – called marginals – record the presence of sea turtles, likely Syllomus aegyptiacus or Caretta, possibly Caretta patriciae, the two most common species from the Lee Creek Mine according to Zug (2001). Another fragmentary bone is identifiable as a parasphenoid bone – a bone located deep in the skull – of a billfish (swordfish and marlins). Sturgeons are represented by a fragment of dermal or skull bone with distinctive pitting – sturgeon are among the more common fish from the mine. The fourth non-cetacean is a proximal humerus fragment from some kind of large alcid bird – possibly Pinguinus alfrednewtoni, an extinct flightless penguin-like auk, and the fossil ‘ancestor’ of the recently extinct (ca. 1840s) Great Auk. More detailed comparisons with razorbills (genus Alca) are necessary.

Noncetaceans from the Cone whale assemblage, including five chelonioid sea turtle shell fragments, a billfish parasphenoid (long element right of center), a sturgeon bone (top right), and a proximal humerus of a large alcid, cf. Pinguinus alfrednewtoni (rightmost)

Noncetaceans from the Cone whale assemblage, including five chelonioid sea turtle shell fragments, a billfish parasphenoid (long element right of center), a sturgeon bone (top right), and a proximal humerus of a large alcid, cf. Pinguinus alfrednewtoni (rightmost). Photo by R. Boessenecker

Pygmy sperm whales

Shortly after Lee brought in the remaining parts of the skeleton, I made a surprising discovery – three additional squamosal bones of a much smaller cetacean. The squamosal is a paired skull bone, so there should only be two – not only does the skull of Lee’s whale have a squamosal, it’s also gigantic. So, there is a minimum of three cetaceans present (based on squamosals) – one large mysticete, and two smaller cetaceans. The smaller squamosals are identifiable as pygmy sperm whales (Kogiidae) based upon their size and shape. Shortly after I began noticing fragments of bone mixed in that were composed of a much finer porosity – individual pores in the bone were tiny and under half a millimeter rather than the much coarser pores in the mysticete. The bones are also much, much lighter, and a distinct difference in density was apparent. After an hour or so I had pulled out dozens and dozens of fragments – indicating that much of the skulls would come together. After about 5 or 6 hours of piecing, it is apparent that not only are there two individual pygmy sperm whales, but at least two genera present.

Kogiid skulls from the Cone whale assemblage, Aprixokogia (left) and cf. Scaphokogia (right) Photo by R. Boessenecker

Kogiid skulls from the Cone whale assemblage, Aprixokogia (left) and cf. Scaphokogia (right) Photo by R. Boessenecker

One of these is similar to Aprixokogia kelloggi already reported from the Yorktown Formation (Whitmore and Kaltenbach, 2008), but also a second smaller taxon that appears closer to Scaphokogia cochlearis from the upper Miocene of Peru – though incomplete, the second skull has a more elongate rostrum than other kogiids. Sperm whales in general are freaky – they have highly asymmetrical skulls, and pygmy sperm whales are even weirder, completely lacking nasal bones. Scaphokogia has a bizarre elongate rostrum that makes other kogiids look well-adjusted and normal odontocetes.

More baleen whales

The first part of the skull I saw was the well-preserved earbones – and I saw this gorgeous little petrosal with attached posterior process and an associated bulla, and remarked “ooh it’s a minke whale!” The earbones are the same taxon which was identified earlier by Whitmore and Kaltenbach (2008) as Balaenoptera sp., cf. B. acutorostrata – something close to the modern minke whale. He then showed me a second petrosal, which I thought was a gray whale and not associated with the skeleton. Later on, I flipped the braincase over and the posterior process was in place still – and much, much larger than the minke whale petrosal. Instead, the gray whale petrosal fit in right in place. This meant that based on earbones, at least two baleen whales were present in Lee’s assemblage!

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Mysticete earbones from the Cone whale. Petrosal of the cone whale (left) and the petrosal and associated bulla of Balaenoptera sp., cf. B. acutorostrata. Photo by R. Boessenecker

The plot thickened yet again when I started looking at vertebrae, because various smaller vertebrae are mixed in to the assemblage. A second atlas and axis are present – and are much smaller, possibly representing the same Balaenoptera individual. Unfortunately, the atlas is much larger than the axis, and they do not fit together – meaning that there is a minimum of three baleen whales based on vertebrae!

Cervical vertebrae of the Cone whale assemblage. Atlas (bottom left) of the Cone whale, and smaller atlas of a second mysticete (just above). Axis (bottom right) of the Cone whale, and an even smaller partial axis of a third mysticete (just above).

Cervical vertebrae of the Cone whale assemblage. Atlas (bottom left) of the Cone whale, and smaller atlas of a second mysticete (just above). Axis (bottom right) of the Cone whale, and an even smaller partial axis of a third mysticete (just above). Photo by R. Boessenecker

Why so many species?

In sum, at least one sea turtle, one bird, two types of fish, two pygmy sperm whales, and three baleen whales are preserved in Lee’s assemblage. How could all this get deposited in the same spot? The Yorktown Formation is characterized by slow sedimentation rates, and is punctuated by several internal bonebeds formed during periods of slow or non-deposition. Slow deposition need not rearrange skeletal assemblages to the point of completely mixing them, but hundreds or thousands or hundreds of thousands of years may have passed with the deposition of only a single meter of sediment – enough to keep the main skeleton’s bones together, but providing ample time to preserve additional specimens vertically near the horizon of the skeleton. This is called a “condensed section” in stratigraphy.

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Boessenecker et al. 2014 in PLOS One

Secondly, all of this went through a dragline and was dumped – so the skeleton shifted somewhat, requiring much piecing together, but the skull and jaws and vertebrae were sort of close to anatomical position. It’s therefore possible that mining operations may have mixed in material as well. Regardless of the process by which these remains were concentrated – geological or anthropogenic – we truly received a gift that has kept on giving. Once again, Thanks Lee!

 

Further Reading

S. L. Olson and P. C. Rasmussen. 2001. Miocene and Pliocene birds from the Lee Creek Mine, North Carolina. Smithsonian Contributions to Paleobiology 90:233-365

N. A. Smith and J. A. Clarke. 2011. An alphataxonomic revision of extinct and extant razorbills (Aves, Alcidae): A combined morphometric and phylogenetic approach. Ornithological Monographs 72(1):1-61

J. Velez-Juarbe, A. R. Wood, and C. Pimiento. 2016. Pygmy sperm whales (Odontoceti, Kogiidae) from the Pliocene of Florida and North Carolina. Journal of Vertebrate Paleontology e1135806

F. C. Whitmore and J. A. Kaltenbach. 2008. Neogene Cetacea of the Lee Creek Phosphate Mine, North Carolina. Virginia Museum of Natural History Special Publication 14:181-269

G. R. Zug. 2001. Turtles of the Lee Creek Mine (Pliocene: North Carolina). Smithsonian Contributions to Paleobiology 90:203-218

 

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Friday Fossil Feature – 50 Shades of Gray (whale, that is)

by Robert Boessenecker (@CoastalPaleo) and Sarah Boessenecker (@tetrameryx)

Happy Fossil Friday! We’re back after a long hiatus, to talk about our most recent donation – A new gray whale from the Lee Creek Mine, NC, donated by Lee Cone.

Lee Cone with the skull he excavated and donated to CCNHM. Photo by R. Boessenecker

Lee Cone with the skull he excavated and donated to CCNHM. Photo by R. Boessenecker

The PCS phosphate mine (aka Lee Creek Mine) near Aurora, North Carolina, preserves one of the largest and most diverse assemblages of fossil marine vertebrates anywhere on earth. The marine mammal assemblage is similarly one of the world’s more important assemblages – up there with Sharktooth Hill (California, USA), the Pisco Formation (Peru), Waitaki Valley (Oligocene, NZ), Calvert Cliffs (Maryland, USA), and the Oligocene Ashley/Chandler Bridge formations right here in Charleston. The richly fossiliferous Pungo River Limestone (Oligo-Miocene) is overlain by the Pliocene Yorktown Formation; the Pungo is highly phosphatic, and is the major ore-bearing unit at the phosphate mine (the base of the Yorktown is also targeted). During these mining operations, embarrassingly rich assortments of fossils are unearthed. Shark teeth, fish bones, and bird bones are often preserved hole – but the destructive mining process tends to separate associated skeletons and break bones up into smaller pieces. Sharks, fish, and birds are often identifiable based on isolated bones – but cetaceans (whales and dolphins) are generally not, with the exception of earbones, skull parts, and jaws.

Partial cranium of the new whale. Photo by R. Boessenecker

Partial cranium of the new whale. Photo by R. Boessenecker

Whale and dolphin earbones are commonly found in both of the major units in the Lee Creek Mine, and tend to survive mining activities. Earbones are highly distinctive and easy for paleocetologists to identify – but when isolated, do nothing more than act as a register of a particular species at a particular place and time in earth’s history. More complete remains are generally needed to name new species and examine their evolutionary history.

Partial cranium of the new whale. Photo by R. Boessenecker

Partial cranium of the new whale. Photo by R. Boessenecker

 

President of the Special Friends of the Aurora Museum and fossil collector extraordinaire Lee Cone just donated to CCNHM a spectacular whale skeleton he collected over several weeks in 2006 prior to closure of the mine. The skeleton had gone through a dragline but dumped with skull, jaw, and postcranial remains in near-correct position. Though fragmented, Lee was able to piece back together quite a lot of the specimen. It includes a partial skull, earbones, mandibles, vertebrae, and ribs (and perhaps other postcrania).

Skeletons like this are extremely rare at the mine – visitors often only have a single morning to collect, and mining operations tend to destroy skeletons like this. In fact, even skulls and skull parts are rare; nearly every partial skull from the mine has either been named, described, or designated as a holotype specimen. Associated marine mammal skeletons – and baleen whales at that – are almost unheard of.

Rostral elements of the new whale. Photo by R. Boessenecker

Rostral elements of the new whale. Photo by R. Boessenecker

The baleen whale assemblage from the Pliocene Yorktown Formation includes a dwarf right whale (Balaenula sp.), a bowhead whale (Balaena ricei), a minke whale-like species (Balaenoptera sp., cf. B. acutorostrata), an extinct and very poorly known larger rorqual (“Balaenoptera borealina”), a possible humpback whale (Megaptera sp.), a gray whale (Gricetoides aurorae), and two dwarf cetotheriid baleen whales (Herpetocetus transatlanticus, Herpetocetinae n. g.). A recent donation to CCNHM from the estate of Rita McDaniel, an avid collector who amassed a spectacular collection of fossils from the mine, includes 16,000 specimens with hundreds upon hundreds of whale and dolphin earbones. This collection indicates the presence of at least one or two additional baleen whales – including a second gray whale, an undetermined genus that is perhaps closer to the modern gray whale (Eschrichtius robustus) than Gricetoides is.

Periotics, which will aid in identifying if this whale is a new genus or species. Photo by R. Boessenecker

Periotics, which will aid in identifying if this whale is a new genus or species. The leftmost specimen is associated with the new whale, the two specimens to the right are from the McDaniel collection donated earlier this year. Photo by R. Boessenecker

Before Lee Cone brought the specimen to CCNHM, I knew that because most of these species are represented only by material far less complete, the odds were good that the specimen would be highly significant and either 1) represent a name-able species or new genus and species, or 2) represent a publishable specimen expanding the known morphology of a pre-existing species (e.g. Gricetoides). As it turns out, this specimen shares the unique earbone morphology of the second gray whale from the McDaniel Collection – and differs in some ways from Gricetoides, confirming the presence of two gray whales in the Yorktown Formation. Lee’s whale looks to be a future holotype specimen, representing either a new species or a new genus as well!

 

Further Reading:

F. C. Whitmore and J. A. Kaltenbach. 2008. Neogene Cetacea of the Lee Creek Phosphate Mine, North Carolina. Virginia Museum of Natural History Special Publication 14:181-269

F. C. Whitmore and L. G. Barnes. 2008. The Herpetocetinae, a new subfamily of extinct baleen whales (Mammalia, Cetacea, Cetotheriidae). Virginia Museum of Natural History Special Publication 14:141-180

C.-H. Tsai and R. W. Boessenecker. 2015. An Early Pleistocene gray whale (Cetacea: Eschrichtiidae) from the Rio Dell Formation of northern California. Journal of Paleontology 89(1):103-109
C.-H. Tsai, R. E. Fordyce, C.-H. Chang and L.-K. Lin. 2014. Quaternary fossil gray whales from Taiwan. Paleontological Research 18(2):82-93
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Friday Fossil Feature – A Closer Look at the Echo Hunter

By Robert Boessenecker (@CoastalPaleo) and Sarah Boessenecker (@tetrameryx)

Happy Fossil Friday!

Echovenator sandersi, the Echo Hunter. Image Source.

Echovenator sandersi, the Echo Hunter. Image Source.

We all know that odontocetes (toothed whales and dolphins) use echolocation – this bio-sonar allows them to find their way under water and hunt their prey. They send a series of ‘pings’ out and listen for the echo with specialized organs and facial structures that allow them to be successful predators, and even differentiate shapes!

Recently, a new paper was published describing a fossil dolphin from the Charleston area that supports an earlier origin than previously thought for ultrasonic hearing & echolocation in toothed whales. This dolphin, named Echovenator sandersi, is a xenorophid dolphin from the Chandler Bridge Formation, which is late Oligocene in age (26-23 million years old).

Xenorophidae are the oldest and most primitive known group of Odontoceti; they have an anteriorly placed blowhole/melon, heterodont teeth, and a mostly symmetrical skull and also large brain size.

Skull of Echovenator.

Skull of Echovenator.

Other fossils like Cotylocara macei (CCNHM collections) demonstrate that xenorophids already had ability to produce sounds for echolocation, owing to a series of unique sinuses and other structures in the facial region of the skull.

In a separate recently published paper, a single xenorophid periotic (inner earbone) was recently analyzed using micro-CT (computed tomography) and found capable of hearing ultrasonic frequency sounds; however, identification of this periotic is unclear and not associated with a skull.

Periotic of Echovenator.

Periotic of Echovenator.

Echovenator preserves earbones with loosely coiled cochlea and other features indicative of ultrasonic hearing as in modern Odontoceti. New analysis suggests that high frequency hearing is the primitive condition for all cetaceans, and that baleen whales (Mysticeti) and odontocetes diverged early from this ancestral condition, with baleen whales evolving low frequency hearing and toothed whales evolving ultrasonic hearing.

Phylogenetic tree demonstrating the evolution of cetacean hearing.

Phylogenetic tree demonstrating the evolution of cetacean hearing.

This indicates that toothed whales have had the ability to echolocate since the inception of the group at around 34 million years ago, and is a key innovation in whale evolution

Two skulls in CCNHM collections also represent Echovenator, and are either juveniles or perhaps a second species in the newly described genus.

Echovenator specimens in CCNHM Collections. Photo by R. Boessenecker

Echovenator specimens in CCNHM Collections. Photo by R. Boessenecker

 

Further Reading:

Churchill, M., Martinez-Caceres, M., Muizon, C. de, Mnieckowski, J., and J.H. Geisler. 2016. The origin of high-frequency hearing in whales. Current Biology, Online Early [Article Link]

 

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Friday Fossil Feature – An Over-Whale-Ming Donation!

By Sarah Boessenecker (@tetrameryx)

 

Happy Fossil Friday!

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Mark with his gigantic Basilosaurus vert – kindly donated to the CCNHM! Photo by R. Boessenecker.

Today we’re writing to thank local fossil collector, and founder of the Palmetto Paleontological Society, Mark Bunce.

Mark has a passion for fossils, and started our local fossil club 2 years ago; over the years, Mark has made numerous donations to CCNHM, and many of these fossils are proudly on display. At the most recent meeting, he donated a large Basilosaurus sp. vertebrae – nearly 12 inches in length!

Big vertebrae mean big animals! Photo from Wikipedia.

Big vertebrae mean big animals! Photo from Wikimedia Commons.

Basilosaurus was an early whale – one of the earliest! They lived in the Eocene, and grew to huge sizes. With over 70 vertebrae, Basilosaurs was over 50 feet long – making them a deadly predator of the late Eocene seas.

Basilosaurus still retained hind limbs, though they were highly reduced and not capable of supporting weight on land; it was completely restricted to aquatic environments. Though it wasn’t as highly adapted to ocean life as whales of today, likely spending most of its time near the surface and hunting fish, sharks, and potentially other small whales, it had started to develop the features of modern cetaceans in its ear bones – they were separated from the skull with dense bullae, indicating it could hear directionally underwater.

Museums such as CCNHM are made possible through the donations and help of amateur collectors – over 80% of the material in collections and on display at CCNHM are from amateur collectors, most of them in the Charleston area! In fact, we have so much donated material we are busy working on a display case devoted entirely to amateur collectors and their donations.

Thanks again, Mark, for the wonderful donation!

 

Further Reading:

Bejder, Lars; Hall, Brian K. (2002). “Limbs in whales and limblessness in other vertebrates: mechanisms of evolutionary and developmental transformation and loss”. Evolution and Development 4 (6): 445–458. [Link]

Fahlke, Julia M. (2012). “Bite marks revisited – evidence for middle-to-late Eocene Basilosaurus isis predation on Dorudon atrox (both Cetacea, Basilosauridae)” (PDF). Palaeontologia Electronica 15 (3). Retrieved August 2013. [Link]

Fahlke, Julia M.; Gingerich, Philip D.; Welsh, Robert C.; Wood, Aaron R. (2011). “Cranial asymmetry in Eocene archaeocete whales and the evolution of directional hearing in water”. PNAS 108 (35): 14545–14548. [Link]

Ekdale, E. G. and Racicot, R. A. (2015), Anatomical evidence for low frequency sensitivity in an archaeocete whale: comparison of the inner ear of Zygorhiza kochii with that of crown Mysticeti. Journal of Anatomy, 226: 22–39. doi: 10.1111/joa.12253 [Link]

 

 

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Friday Fossil Feature – whale, whale, whale, it seems all is not lost after all!

By Sarah Boessenecker (@tetrameryx) and Robert Boessenecker (@CoastalPaleo)

 

Happy Fossil Friday!

Today we’re looking at Agorophius pygmaeus, one of the first named odontocetes from North America. Agorophius has a long, complicated history –  and it starts right here, in Charleston!

Our partial braincase of Agorophius pygmaeus.

Our partial braincase of Agorophius pygmaeus. Image by S. Boessenecker.

Agorophius pygmaeus was discovered in the 1840’s at Middleton Place, a plantation in West Ashley. It was found in the Ashley Limestone, and was originally named Zeuglodon pygmaeus, from a partial braincase and single tooth.

A popular tourist site, Middleton Place was the site of discovery of the type specimen. Image Source.

A popular tourist site, Middleton Place was the site of discovery of the type specimen. Image Source.

It was heavily studied throughout the 19th century, but the holotype specimen was lost sometime before 1907 when Frederick True attempted to locate it. However, some 140 years later, Ewan Fordyce re-discovered the tooth of the holotype specimen in the collections of the Harvard Museum of Comparative Zoology in 1980, and was able to match it to the illustrations from the original publication. However, the partial skull has never been found again.

The skull was lost in the early 1900's, but the tooth has since been found, and luckily there's incredibly detailed illustrations for comparison. From Godfrey et. al. 2016.

The skull was lost in the early 1900’s, but the tooth has since been found, and luckily there’s incredibly detailed illustrations for comparison. From Godfrey et al 2016.

This missing holotype has wreaked havoc in odontocete taxonomy; Agorophius exhibited many uniquely transitional features and many authors have discussed the “Agorophiidae;” for a long time, Agorophius was one of the only early odontocetes known. The loss of the holotype caused “taxonomic paralysis” – naming of new genus and species was on hold as new specimens couldn’t be compared to the original, else risk bloat and naming new species when they were actually just new specimens of an already named genus or species.

A new paper recently published by Stephen Godfrey et al. (2016) refers two new skulls to Agorophius pygmaeus, one from the Chandler Bridge Formation (23-24 Ma) and another from the older Ashley Formation (~26-29 Ma); both of these specimens include basicrania and earbones, and are somewhat more complete than the lost holotype.

New specimens described in the new paper. From Godfrey et al 2016.

New specimens described in the new paper. From Godfrey et al 2016.

However, neither specimen has teeth, and the only surviving part of the type specimen is a tooth – this means that the identification is based on the original illustrations; various authors have debated whether or not this is kosher. Ultimately, illustrations of Agorophius are extremely detailed and better than many photographs of fossil cetaceans in papers published in the last few decades, and as such are accepted as a means for identification.

This recent paper is a significant leap forward in the study of early odontocetes; CCNHM also has material that is referable to Agorophius or even Agorophius pygmaeus, and gives CCNHM researchers & affiliates a “green light” toward studying our own Agorophius and dwarf agorophiid specimens.

 

Further Reading:

Stephen J. Godfrey, Mark D. Uhen, Jason E. Osborne and Lucy E. Edwards (2016). A new specimen of Agorophius pygmaeus
(Agorophiidae, Odontoceti, Cetacea) from the early Oligocene Ashley Formation of South Carolina, USA. Journal of
Paleontology, 90, pp 154-169 doi:10.1017/jpa.2016.4   [Link]

Fordyce, R. E., 1981, Systematics of the odontocete whale Agorophius
pygmaeus and the Family Agorophiidae (Mammalia: Cetacea): Journal of
Paleontology, v. 55, no. 5, p. 1028–1045.    [Link]

 

 

 

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Friday Fossil Feature – The head bone’s connected to the… neck bone…

By Sarah Boessenecker (@tetrameryx)

Happy Fossil Friday!

Fossils don’t prepare themselves, and rarely come out of the ground looking the way you seem them on display in a museum. Here at the CCNHM, we are building a team of dedicated, hard-working volunteer preparators to help us clear out our backlog of fossil cetaceans!

How fossils are often found in the field - it takes skill and patience to make sense of this! Photo by S. Boessenecker

How fossils are often found in the field – it takes skill and patience to make sense of this. Photo by S. Boessenecker.

Fossil preparation takes time, skill, patience, and a certain eagerness. Cleaning off a fossil is a rewarding experience – you’re the first to see this bone surface in millions of years!

Dental picks and tooth brushes - good for more than just your teeth! Photo by S. Boessenecker.

Dental picks and tooth brushes – good for more than just your teeth! Photo by S. Boessenecker.

We currently have 2 amazing student volunteers; Jordy Taylor is a masters student in the Biology department, working with fossil sharks, and Brad Thompson is an undergrad in the geology department and museum docent.

Using brushes, dental picks, and some hard work, they’re helping us to expose whale and dolphin skulls from the Oligocene of the Charleston area.

Brad's skull - he's doing a fantastic job! Photo by S. Boessenecker.

Brad’s skull – he’s doing a fantastic job! Photo by S. Boessenecker.

Brad’s fossil is a braincase of a medium sized baleen whale from the upper Oligocene (~28 Ma) Chandler Bridge Formation of Summerville, South Carolina – a baleen whale in the family Eomysticetidae, the earliest toothless baleen whales.

Brad working on his mysticete braincase. Photo by R. Boessenecker.

Brad working on his baleen whale braincase. Photo by R. Boessenecker.

Jordy is working on several waipatiid dolphin skulls – two nearly complete skulls in sandstone blocks, and a third fragmentary skull consisting of fragments of a partial braincase.

Jordy working on her Waipatiid skull. Photo by R. Boessenecker.

Jordy working on her waipatiid skull. Photo by R. Boessenecker.

Our docents take photos and detailed notes to document their work. Photo by S. Boessenecker.

Our docents take photos and detailed notes to document their work. Photo by S. Boessenecker.

At least one of these skulls appears to represent the same species as the tusked waipatiid dolphin on display in our whale evolution gallery. Waipatiid dolphins were originally reported from the Oligocene of New Zealand – the first named species is Waipatia maerewhenua, named by R. Ewan Fordyce in 1994.

Our waipatiid dolphin already on display in the museum. Photo by S. Boessenecker.

Our waipatiid dolphin already on display in the museum. Photo by S. Boessenecker.

These dolphins were also common in the Oligocene seas near Charleston, and by preparing these skulls they are helping us to better understand their evolution. A big huge thank-you to our wonderful volunteers!

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Friday Fossil Feature – Thinking of a Good Walrus Pun is No Easy Tusk…

by Sarah Boessenecker (@tetrameryx) and Robert Boessenecker (@CoastalPaleo)

Happy Fossil Friday!

Did you know that walruses used to live in the Southeastern US? From about 4 million years ago to as recently as 300,000 years ago these tusked behemoths were inhabiting in the southern most regions of the North Atlantic – as far south as Florida!

A tusk in the hand is worth 2 in the bush? Photo by R. Boessenecker.

A tusk in the hand is worth 2 in the bush? Photo by R. Boessenecker.

Our Friday Fossil Feature today is a partial tusk from Ontocetus emmonsi, a rare Pliocene walrus found in deposits from the Lee Creek Mine in Aurora, North Carolina, recently donated to CCNHM by the estate of Rita McDaniel. Two more tusks are also present in our collection, and are from South Carolina.

Our newest acquisiton, from Lee Creek, at top; female tusk in middle, and male tusk at bottom, both from South Carolina. Photo by S. Boessenecker.

Our newest acquisiton, from Lee Creek, at top; female tusk in middle, and male tusk at bottom, both from South Carolina. Photo by S. Boessenecker.

Ontocetus has a long history; it was first described in 1859 by Joseph Leidy, based off of a partial tusk from the Yorktown Formation, collected by Ebenezer Emmons, and is now in the collections at the Smithsonian Museum of Natural History (USNM).  Emmons was a professor at Williams College in Massachusetts, and also the State Geologist of North Carolina from 1851-1863, and was honored with Ontocetus being named after him. Many other species of Plio-Pleistocene walruses from the North Atlantic were subsequently proposed, including: Alachtherium cretsii, Alachtherium antwerpiensis, Trichecodon huxleyi, Trichecodon/Odobenus antverpiensis, and Prorosmarus alleni.

IMG_6913

The holotype specimen of Ontocetus emmonsi, from USNM. Photo by R. Boessenecker.

A juvenile maxila and tusk, at USNM. Photo by R. Boessenecker.

A juvenile maxila and tusk, at USNM. Photo by R. Boessenecker.

A monograph published by Naoki Kohno and Clayton Ray (2008) in the Lee Creek Volume IV through the Virginia Museum of Natural History examined and reconsidered specimens of Ontocetus and other walrus material from Atlantic Pliocene deposits. They realized that many species that had been described and presenting problems for scientists were in fact the same species. Rules of zoological nomenclature dictate that if multiple names (synonyms) have been proposed for a single species, the oldest (and thus first proposed) name for a particular species is the correct one. In this case, Ontocetus emmonsi was the first name proposed for the extinct walrus from the Pliocene of the North Atlantic.

Through the simple act of recognizing that all these problematic species represented the same walrus, much confusion was resolved and the range and number of specimens was significantly improved. The larger sample now available from the Pliocene sediments along the North Atlantic margin (Florida, South Carolina, North Carolina, United Kingdom, Netherlands, Belgium, and Morocco) now indicates that Ontocetus was widely distributed down to subtropical latitudes, had shorter and more highly curved tusks than modern walrus, had a more elongate skull, and may have been slightly larger. This walrus had far more of a presence than previously thought in the Pliocene!

 

Further Reading:

J. Leidy. 1859. [Remarks on Dromatherium sylvestre and Ontocetus emmonsi]. Proceedings of the Academy of Natural Sciences of Philadelphia 1859:162

D. P. B. Erdbrink and P. J. H. Van Bree. 1986. Fossil cranial walrus material from the North Sea and estuary of the Schelde (Mammalia, Carnivora). Beaufortia 49(1):1-9

C. R. Harington. 1984. Quaternary marine and land mammals and their paleoenvironmental implications – examples from Northern North America. Special publication of the Carnegie Museum of Natural History 8:511-525.

N. Kohno and C. E. Ray. 2008. Pliocene walruses from the Yorktown Formation of Virginia and North Carolina, and a systematic revision of the North Atlantic Pliocene walruses. Virginia Museum of Natural History Special Publication 14:39-80

K. Post. 2004. What’s in a name: Alachtherium cretsii, de Pliocene van de Nordzee. Grundboor & Hammer 58:70-74.

L. Rutten. 1907. On fossil trichechids from Zeeland and Belgium. Proceedings of the Royal Netherlands Academy of Arts and Sciences 10(1):2-14 

A.E. Sanders. 2002. Additions to the Pleistocene mammal faunas of South Carolina, North Carolina, and Georgia. Transactions of the American Philosophical Society 92:1-152.

 

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Friday Fossil Feature – An investi-Gator of the Oligocene of South Carolina

by Sarah Boessenecker (@tetrameryx)

Happy Fossil Friday!

Dentary of Gavialosuchus americanus. Photo by S. Boessenecker.

Dentary of Gavialosuchus americanus. Photo by S. Boessenecker.

This week we take a look at Gavialosuchus americanus.

Gavialosuchus americanus wasn’t actually an alligator; rather, they were more closely related to today’s gharials and crocodiles. Crocodile puns, however, don’t seem to have the same bite as alligator puns.

Gavialosuchus was a long-snouted crocodylian. Photo by S. Boessenecker.

Gavialosuchus was a long-snouted crocodylian. Photo by S. Boessenecker.

Gavialosuchus lived in estuaries and coastal environments rather than the freshwater habitats its modern relatives prefer; it also grew quite large, growing in excess of 20 feet. That’s as big as today’s saltwater crocodiles!

For prey of Gavialosuchus, a view like this would likely be your last. Photo by S. Boessenecker.

For prey of Gavialosuchus, a view like this would likely be your last. Photo by S. Boessenecker.

Its diet likely consisted of animals commonly found as fossils here in South Carolina, including the Charleston area. These include the dugong Metaxytherium, the river dolphin Pomatodelphis, and shallow water sharks. As Gavialosuchus was a polyphylodont similar to its modern relatives, it was able to constantly replace its teeth throughout its lifetime. Because of this, shed teeth are very commonly found by those hunting for fossils.

 

Teeth of varying ages and sizes, as Gavialosuchus was constantly replacing them. Photo by S. Boessenecker.

Teeth of varying ages and sizes, as Gavialosuchus was constantly replacing them. Photo by S. Boessenecker.

A new tooth emerging. Photo by S. Boessenecker.

A new tooth emerging. Photo by S. Boessenecker.

 

Recently, there’s been some controversy about this taxa; some scientists think that it is the same species as a previously named fossil Thecachampsa americana, as well as a handful of other taxa – this just goes to show the more specimens we find of an extinct animal, the larger our data set becomes, and we’re able to piece together better how these animals lived and evolved. Science is always evolving as we learn more!

Further Reading:

Erickson, Bruce R.; Sawyer, Glen T. (1996). The estuarine crocodile Gavialosuchus carolinensis n. sp. (Crocodylia: Eusuchia) from the late Oligocene of South Carolina, North America. The Science Museum of Minnesota St. Paul, Minnesota Monograph 3, Paleontology. St. Paul: The Science Museum of Minnesota. pp. 1–47.

Myrick, A.C., Jr. (2001). “Thecachampsa antiqua (Leidy, 1852) (Crocodylidae: Thoracosaurinae) from the fossil marine deposits at Lee Creek Mine, Aurora, North Carolina, USA”. Smithsonian Contributions to Paleobiology 90: 219–225.

 

 

 

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Friday Fossil Feature – Kogia let us tell you about earbones again?

By Robert Boessenecker (@CoastalPaleo) and Sarah Boessenecker (@tetrameryx)

For Fossil Friday this week here’s a couple of pygmy sperm whale earbones from the recently acquired Rita McDaniel collection at the Mace Brown Museum of Natural History. McDaniel led mine tours into the Lee Creek Mine (Aurora PCS phosphate mine, North Carolina) for many years, and collected a substantial amount of fossil material from the middle Miocene Pungo River Limestone and the younger overlying lower Pliocene Yorktown Formation. The Yorktown Formation has produced one of the most important assemblages of Pliocene marine vertebrate fossils worldwide and is an important point of comparison for students of shark, fish, seabird, seal, and cetacean evolution.

Some of the earbones in our collection; modern Kogia on the left, and Kogiidae indet. on the right. Photo by Sarah Boessenecker.

Some of the earbones in our collection; modern Kogia on the left, and Kogiidae indet. on the right. Photo by Sarah Boessenecker.

The modern dwarf and pygmy sperm whales (Kogia simus and Kogia breviceps) are tiny sperm whales clocking in at only 2.5-3.5 meters long (approximately the size of a bottlenose dolphin), a fraction of the size of the more publicly known giant sperm whale (Physeter macrocephalus ) of Moby Dick fame (20 meter length). Both species of Kogia are rarely seen alive, and little information is known about their behavior or ecology. Similar to the extant giant sperm whale the fossil record includes many other extinct genera within the family Kogiidae and demonstrates that they evolved from somewhat larger ancestors, with a higher diversity in the late Miocene and Pliocene.

The modern pygmy sperm whale; an elusive creature, most of our knowledge about them comes from strandings rather than live sightings. Image Source.

The modern pygmy sperm whale; an elusive creature, most of our knowledge about them comes from strandings rather than live sightings. Image Source.

At the Lee Creek Mine, a larger kogiid whale is known from a well-preserved skull from the Pliocene Yorktown Formation – Aprixokogia kelloggi – which primitively retained upper teeth. When this species was named, hundreds of isolated well-preserved inner ear bones (periotics/petrosals) were also known, but not associated with the skull. Because of the lack of overlapping parts, the earbones were simply identified as Kogiidae indeterminate. These earbones are quite a bit larger and more robust than extant Kogia spp., which has dainty little periotics.

The 3 modern species of sperm whales. Image source.

The 3 modern species of sperm whales. Image source.

A new study published by Jorge Velez-Juarbe, Aaron Wood, and Catalina Pimiento reevaluates kogiid earbones from the Yorktown Formation of North Carolina and Bone Valley Formation of Florida, and reports previously unrecognized periotics of modern Kogia from the Yorktown Formation, preserved side-by-side with a larger, less modernized pygmy sperm whale (Aprixokogia). These earbones of Kogia are much more rare than the larger variety, and we were lucky enough to receive one of these in our recent donation. Check out our earbone of Kogia side by side with the larger unidentified kogiid – a puzzle answered by this new paper from our colleagues!

Further Reading:

Jorge Vélez-Juarbe, Aaron R. Wood & Catalina Pimiento (2016): Pygmy
sperm whales (Odontoceti, Kogiidae) from the Pliocene of Florida and North Carolina, Journal
of Vertebrate Paleontology, DOI: 10.1080/02724634.2016.1135806 [Full Article]

 

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