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Showing results for tags 'oligocene'.
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From the album: Vertebrates
Aeoliscus longispinus (Rozhdestvensky, 1949) Oligocene Menilite shale Carpathians Jamna Dolna Poland -
This species belongs to a small order of marine ray-finned fishes, the Zeiformes. The order consists of about 40 species in six (or seven?) families, mostly deep-sea types: Zeidae (Dories), Parazenidae (Parazen), Zeniontidae, Oreosomatidae, Grammicolepidae, Cyttidae (?) and Caproidae (Boarfishes). Zeiformes are considered to be the sister taxon of a group making up the order Beryciformes and a huge conglomeration of spiny-rayed fishes known as the "percomorpha", including the Perciformes. They range in size from less than 5 cm to up to 90cm. Zeiformes are characterized by usually thin and deep, compressed, and oblong to disk-shaped bodies with 5 -10 soft rays and possibly a spine in the pelvic fins, 5 -10 dorsal fin spines and up to 4 anal fin spines. The upper jaw with minute, slender conical teeth is more or less protrusible. With their greatly compressed head and body, large mouth, and extremely protrusible upper jaw, the Zeiformes are successful ambush predators. They slowly approach an unsuspecting small fish by means of undulating waves of the transparent soft dorsal and anal fins. In one quick motion they drop the "trapdoor" lower jaw, shoot out the upper jaw, and expand the gill cavity, sucking in the hapless prey along with a considerable volume of water. Zeiform fishes are carnivores; they feed mainly on a variety of fishes but also consume cephalopods and crustaceans. This fish here is an Antigonia sp. from the menilith shales of Bircza in the Polish Carpathians. Antigonia sp. is a member of the family Caproidae (Boarfish, Capros = boar from the Greek kapros). Boarfish are small, with only a few species known to reach a maximum total length of 30 centimetres (12 in) and most reaching less than half that figure. All members of this order are characterized by a laterally compressed body that is as high as it is long. Boarfishes typically have three spines and 25 to 35 soft rays in the anal fin. The pectoral fins are rounded, the pelvic fins set below them (1 stout spine and 5 slightly softer finrays). The first dorsal fin consists of about nine to ten spines, the third being the longest and the strongest. The second dorsal fin consists out of 25 to 35 soft rays. The large eye is well suited to its habitat in deep marine waters ranging from 40m to 600m. The protractile mouth, forming a small tube when protruded, is perfect for catching small copepods, mysids, benthic crustaceans and worms. The living species are all characterized by red, pink or silvery coloration. Swidnicki, J. 1986. Oligocene Zeiformes from the Polish Carpathians. - Acta Palaeontologica Polonica, Vol 31, No. 1-2, 111-135. http://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Boarfish_(_Antigonia_capros_).jpg/300px-Boarfish_(_Antigonia_capros_).jpg picture from wikipedia
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From the album: Vertebrates
Properca sabbae Pauca 1929 Oligocene Rowne Poland -
Last Friday I went with a group of people to a local North Carolina Oligocene Quarry. This quarry contains exposures of the late Oligocene Belgrade Formation; Pollocksville and Haywood Creek members along with the early Oligocene river Bend Formation. These are all in situ pictures. The drive in .... These piles are mostly Pollocksville member, but there is some Haywood Creek member of the Belgrade mixed in. There is also a pebble lag that has Pleistocene and Pliocene fossils. First find of the day was this nice little croc tooth, Thecachampsa sp. A little later I found this nice cowshark tooth, Notorhynchus cf. primigenius and this nice little croc vert .....
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I bought this jaw at a fossil show and the only info that came with it was "Badlands USA". The matrix looks Miocene Arikaree to me and not Oligocene but I'm not sure of course. Any information from a mammal/tooth collector will be appreciated. I have an idea of what it might be but I don't want to say anything until I hear from you all. Thanks, Mikey
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A new mysticete-related paper is available online: Hernández Cisneros, Atzcalli Ehécatl. 2018. A new group of late Oligocene mysticetes from México. Palaeontologia Electronica 21.1.7A 1-30. https://doi.org/10.26879/746 palaeo-electronica.org/content/2018/2147-oligocene-mysticetes-from-mexico The discovery of Tlaxcallicetus represents the second named species of Oligocene chaeomysticete from the eastern Pacific and only the third named species of Paleogene mysticete from that region, the other being the late Eocene Mystacodon from Peru. Thanks to the discovery of Sitsqwayk from Washington State, Tlaxcallicetus shows how much more is to be learned about early chaeomysticete diversity in the Pacific because the vast majority of Pacific chaeomysticetes from the Oligocene have been found in New Zealand (it's possible that there may be an undescribed Oligocene mysticete fossil in museum collections in California, or mysticetes preferred pelagic habitats in California in contrast to the Pyramid Hill odontocetes).
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Hi, I recently finished processing 4kg of matrix from a horizon in the Upper Hamstead Mbr. of the Bouldnor Fm. from Bouldnor Cliff and thought I'd share the results! The White Band is definitely the most diverse vertebrate fauna I've collected so far in my short time screen washing, with at least 2/3 genera of fish, 2 genera of reptiles, and 2 genera of mammals, it also has some interesting taphonomy. The White Band refers to a thick Polymesoda shell bed in the Upper Hamstead Mbr. and dates to approximately 33 million years bp during the Rupelian. The Upper Hamstead Member is the youngest strata in the entire paleogene sequence of the Hampshire Basin (Late Palaeocene to Early Oligocene). The horizon was deposited in a shallow freshwater lacustrine environment on the low-lying Solent Group coastal plain of the southern Hampshire Basin. By the time the White Band was deposited average annual temperatures in the region were beginning to warm up again after the sudden and rapid cooling that marked the Eocene-Oligocene transition. Global sea levels were also beginning to rise. The Grande Coupure, the large scale turnover of European mammalian faunas had been and gone, and the endemic Eocene groups such as Palaeotheres, Omomyid primates, and anoplotheres had long vanished. The lake/pond system that deposited the White Band was home to aquatic plants such as Stratiotes and was fringed by patches of open woodlands of Sequoia, Pine, and broadleaf. With the post-grande coupure fauna now established the landscape was home to anthracotheres, hornless rhinos, hyaenodonts, bear-dogs, entelodonts, primitive ruminants, choeropotamids, and a myriad of smaller mammals including bats, adapid primates, rodents, insectivores, marsupials, and the otter-like pantolestids. Not to mention the alligators, birds, and freshwater turtles. 1. Worn fragment of Emys carapace 2. Possible fragment of crocodilian osteoderm? 3. Fragment of Bowfin skull bone 4. Isoptychus sp. cheek tooth. Theridomyid rodents like Isoptychus are the most commonly found micro-mammal throughout the entire Solent Group. This molar has been heavily worn which may suggest an older individual. Theridomyids were bipedal and foraged along the ground and in low trees. They also seem to have fed on the seeds of marginal aquatic plants such as Stratiotes, which may be the reason this individual was in the vicinity of the pond/lake. The Theridomyids were one of only a few Eocene mammal groups to survive the Grande Coupure and seemed to have survived fairly unscathed in terms of diversity etc. showing what hardy and adaptable rodents they probably were. 5. Fragment of M3 from a talpid, most likely Myxomygale sp. (just 1.5mm long!). Talpids (or as we call them today, Moles) were newcomers to Europe with the Grande-Coupure, arriving from Asia. Belonging to the tribe Urotrichini (Shrew-Moles) which are only found in North America and Asia today, Myxomygale may have spent most of the day underground in burrows before emerging at night to feed on invertebrates. Modern Shrew-Moles prefer moist habitats such as swampy areas, a habitat which was abundant on the low-lying coastal plain of the Oligocene Isle Of Wight. The taphonomy of the White Band is also interesting. Some specimens i.e. the Emys fragment and osteoderm are highly 'polished' and worn, suggesting transport prior to deposition. Whereas others such as the mammals and most fish material I've recovered are unworn and 'fresh' looking. I'm not sure what conditions could have caused this, and if anyone has any suggestions I'd be really interested. My take is that the mammals and fish were likely living in the immediate area, in and around the lake/pond, whereas the polished material is from animals living some distance away brought to the pond/lake by floods or streams etc. although I'm no trained geologist or palaeontologist. Thanks for reading, Theo
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tertiary crinoid. Articulated tertiary specimens, very rare Lit.: Moore, R. C. & Vokes, H. E. 1953. U.S.Geol.Survey Prof.Paper. 233-E: 124, Pl 23, fig 1, 3.
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Fragment of M3 from a talpid (cf. Myxomygale sp.) collected through screen washing of matrix from the White Band.
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Partial crushed left mandible from the anthracothere Bothriodon collected from the Bouldnor Formation in two pieces. The first collected ex-situ on the 29/01/18, and the second on 13/02/18. P2 to M3 in-situ. P1 and M2 missing.
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Hi, I thought I'd share some of my best finds from what has been a brilliant start to collecting in 2018! The Isle Of Wight has been hit by heavy storms, with torrential rain and gale force winds, numerous times over the last month or so. This has caused some serious erosion and slipping to the soft clay cliffs and foreshore of the Bouldnor Fm. and the coast has been highly productive. I've made some of the best finds of my fossil hunting "career" (if that's the right term for it), including some very nice large mammal finds that I have dreamed of coming across for a while now. 1. The partial cranium of a mammal. This is without a doubt one of my best finds. I collected it ex-situ from the foreshore and at first thought I was looking at a large piece of fossil wood, which are common in some of the fluvial and freshwater horizons of the Lower Hamstead Member. Luckily I spotted the cancellous bone texture, and quickly realised it was a large piece of mammal skull. The cranium is essentially the left portion of the brain case with the parietal bone, part of the frontal bone, jaw articulation surfaces and saggital crest with scars from the temporalis muscle. The brain case is filled with sediment and Viviparus gastropods, which may be the culprits for the extensive mollusc bore marks on the parietal bone. There is also a Stratiotes seed in one of the gastropod shells indicating the skull was deposited in a shallow (less than 6.5m deep) freshwater pool, probably already broken. Skulls like this are incredibly rare, and I've heard that it looks like it was probably out on the shore for just a couple of hours! As usual with my big or unusual finds I took it straight in to Dinosaur Isle Museum where it's currently on loan for preparation and identification in case it's an important find. I believe it may be something like an Anoplotherium although I'm not sure. 2. Partial Bothriodon mandible. This is a really cool find that I've always wanted to come across! Bothriodon is an abundant part of the Post-Grande Coupure mammal fauna, arriving in Europe and Britain around 33.6 million years ago from Asia. This was facilitated by the Oi-1 glaciation event in Antartica lowering global sea levels and opening up several migration routes from Asia into Europe for a myriad of immigrant taxa. The habitat of the early Oligocene Hampshire Basin was ideal for the proposed lifestyles of anthracotheres (low lying coastal plain with wetlands, lakes, and open woodland), which along with a preservation bias, makes Bothriodon the most common large mammal encountered. I found this jaw in two pieces, 14 days apart and 5m from each other in a mudflat at low tide. The bone is heavily crushed and has P2 - M3 in-situ, although P1 is missing (possibly pre-fossilisation) and I still haven't found the other jaw section with the M2 (fingers crossed it'll turn up one of these days!). I think the jaw washed out of the Upper Hamstead Member during this winter's storms and smashed into several pieces which were subsequently scattered over the immediate area. (P1 to M1 section found 14 days after the M3)
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From the album: Vertebrates
Antigonia sp. Menilite Formation Oligocene Jamna Dolna Bieszczady County Poland -
Cheek tooth from the theridomyid rodent Isoptychus sp. Collected through screen washing of matrix from the 'White Band' a shallow freshwater lacustrine horizon.
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Found on N Topsail Beach, NC, in October of 2015 (not long after a dredging and sand replacement project). Longest edge is 6 cm. Various "authorities" have offered conflicting id's. I don't have many fossils worth showing anybody and I'd like to be able to tell visitors definitively what it is. I did read the various threads on this topic in the forum and looked it up in other sources, as well. However, I found researching Carcharocles auriculatus vs Carcharocles angustidens much like watching a pack of hound dogs turned loose on a truckload of rabbits released in the forest. Would appreciate opinions from those knowledgeable on the current theories regarding this (apparent) debate. Or is it just evolution of opinion?
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Hi, I've recently fully processed some matrix from the Lower Hamstead Mbr. that I collected back in November, and I thought I'd share some of my finds in a similar way to my Bembridge Marls Mbr. material. The matrix originates from a 'shelly' horizon in the Lower Hamstead Mbr. and was collected from fallen blocks at the base of a low cliff exposure at Bouldnor Cliff. The Lower Hamstead Mbr. overlays the late Eocene Bembridge Marls and dates from the very earliest Oligocene epoch, approximately 33.75 - 33.5 million years ago. To put the finds into an environmental context the Lower Hamstead Mbr. was deposited during a period of rapid global cooling and drop in sea levels associated with the onset of antarctic glaciation (Oi-1). The cooling and eustatic change had begun in the late Eocene, with the palaeo-environments of the Bembridge Marls becoming increasingly terrestrial towards the Eocene/Oligocene boundary. By the Lower Hamstead Member the southern Hampshire Basin was a low lying coastal plain with extensive wetlands, lakes, ponds and sluggish rivers flowing south east towards the early channel (at this time the channel was more a large embayment with only occasional connection to the North Sea). The dense sub-tropical forests of the late Eocene had disappeared and the landscape was dominated by open woodlands of pine, sequoia, and oak. The environment was much cooler and annual rainfall had significantly dropped since the Eocene, although temperatures would begin to rise again further into the rupelian and Hamstead Mbrs. The basin was surrounded by areas of chalk upland (still existing today) with forests of sequoia and broadleaf species. This dramatic climate change is likely what triggered the Grande Coupure, in which endemic Eocene mammals like the palaeotheres disappeared and were replaced with Asian groups such as carnivorans, rhinocerotids, anthracotheres, and a variety of other artiodactyls. The mammals of the dense tropical Eocene forests simply couldn't adapt fast enough to the new open environments of the Oligocene and ultimately failed to compete against the better adapted migrants. By the Upper Hamstead Member the mammals on the Hampshire Basin coastal plain are almost entirely of Asian origin. Therefore the micro-vertebrates lived in an environment of large scale climatic and ecological change, which I think adds another level of interest to collecting from this member of the Bouldnor Fm. The material I've collected so far is a lot more varied than the Bembridge Marls, but overall is less abundant. So far it's produced at least 3 fish taxa, 2 mammals, and an indeterminate piece of jaw which may be reptilian or mammal. 1. A skull element from a Bowfin (Amia sp.), these fish are very common in most horizons of the Bouldnor Fm. 2. A vertebra from a Bowfin (Amia sp.) 3. A damaged lateral scute from a Sturgeon (Acipenser sp.) showing the transition to a freshwater environment 4. An indeterminate piece of a tiny jaw, may be crocodilian although I'm not sure. 5. The nicest find of the lot, a lower incisor from the theridomyid rodent Isoptychus (ID'd by Jerry hooker from the NHM). These rodents looked similar to modern kangaroo rats, hopping along the ground on large rear legs. Bite marks on Isoptychus bones collected from Thorness Bay suggest that they were common prey for the bear-dog Cynodictis. 6. Finally 2 images of an unidentified mammal tooth. I'm unsure as to whether this is part of the tooth or the entire crown, but it doesn't appear to be from a rodent. Hope you all enjoyed the finds, Theo
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This is from a site in eastern NC where everything found is Eocene, Castle Hayne Formation. It looks like Rhincodon, which is Oligocene. Could it be a transition tooth, or is this something entirely different? I dont see any signs of worn down side cusps but the root itself appears to be worn down or fragmented. Scale is mm. Thanks
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Hello everyone, I bought this tooth a while back from @Sharks of SC and it’s been nagging at my brain for a while. SOSC came to the conclusion it is a thresher tooth (and I do agree) but it has two cusps. As far as I know, Trigonotodus alteri is the cusped variety of giant thresher, but usually only has one cusp each side. I seem to remember seeing another double cupped thresher for sale a long time ago, but one of the cusps was very reduced. Information on these guys is incredibly scarce, so I was wondering what your (the clever people who inhabit this forum) thoughts were on it. It’s from the chandler bridge fm (oligocene) in SC, although Miocene fossils sometimes find their way in. According to SOSC other thresher teeth were found at the site. I considered the possibility of serratolamna, but none looked quite right and the age makes it very unlikely (though I suppose a thresher based on overall rarity is unlikely). SOSC’s pictures, I’m horrid at photography. About an inch slant height Thanks for any help! These threshers sure are interesting, I think I might have to start a thresher sub-collection...
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Hi, I headed out for a full day of collecting at Hamstead on Saturday, and thought I'd share how it went. I reached the beach at Hamstead Duver around 9am and began searching the foreshore. The finds on this part of the coast are washed round by longshore drift, but it can be a productive section. This was definitely the case on Saturday, within the first 20 odd metres I picked up various pieces of trionychid carapace, Emys fragments, and the worn trochlea of an anthracothere humerus. I continued west along the coast before reaching the slipway (a disused boat launching ramp, apparently used by the US military in preparation for the Normandy Landings) the point where Hamstead Cliffs begin. Having not been able to visit in nearly a month, and after weeks of pretty violent storms over Christmas and the New Year, the coast at Hamstead Ledge has now completely changed. Most of the sand and gravel has been taken off the beach leaving large exposed areas of Bembridge Marls strata on the foreshore. The junction bed between the underlying Bembridge Limestone and Bembridge Marls is also now visible (usually obscured by sand and gravel). The Bembridge Limestone Fm. lays beneath the Bouldnor Fm. and was laid down in a series of large carbonate lakes on a heavily forested sub-tropical coastal plain stretching across what is now the northern Island. At 34.0 million years ago rising sea levels flooded the plain and the estuary/lagoons of the lower Bembridge Marls were deposited, which can be observed in the low cliff face. (A small normal fault can be seen in the Bembridge Marls highlighted in yellow, additionally the 'thin white horizon' is the western limits of the famous Insect Limestone. However it is un-lithified and does not produce insects at this locality) The largest change however was an enormous landslide just west of the ledge in the high cliff face. As well as several smaller falls and slips, this slip has littered the beach with clay debris and small trees. It's on the site of a large mudflow from last winter, I reckon the heavy rain saturated the already weakened area and triggered a large scale failure of the cliff face. I checked through the debris (and the exposed strata) and found some very nice pieces, including a huge piece of trionychid hypoplastron (the largest turtle piece I've ever found), a fragment of alligator jaw, a large fish vertebra, and two large baso-occipital bones from Bowfins (Amia sp.). As the beach was covered with clay blocks the foreshore wasn't very productive for ex-situ finds. As the tide dropped I moved further west towards Cranmore and beach conditions returned to normal with shingle, sand, and gravel, and a nice variety of finds. The best finds were a couple of anthracothere teeth, including a very nice canine. Coprolites were also very common as usual, most, if not all, are likely crocodilian. Further west there are exposures of the Upper Hamstead Member on the foreshore which if you're lucky turn up in-situ finds. The Upper Hamstead Member dates from approximately 33.2 - 32.4 million years ago. This time I was in luck, I spotted a large bone fragment and a piece of Emys weathering out of the clay. I checked the areas adjacent in case there was anymore associated material but unfortunately not. The bone fragment appears to be a rib. I reached Cranmore and collected some matrix for micro-sieving from the cliff face, and after collecting a few more bone fragments and coprolites, and with the tide now rising I called it a day and headed up to the main road. Overall it was a good collecting trip, with some good finds. Hopefully as the winter goes on the landslide debris is eroded away and some nice vertebrate remains are produced. Hope this was interesting, Theo 1. Huge piece of trionychid hypoplastron 2. 'Interior' view of the hypoplastron
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Hi, I thought I'd share some of my finds from what was a pretty good trip up to Bouldnor Cliff on Tuesday morning. This was my first collecting trip in over a month due to tides, being ill over Christmas and being generally busy, so I missed out on most of December. But hopefully I can start getting back into going twice a week again as usual. Low tide was at 09:48 so I decided to head for Bouldnor instead of Hamstead, as it's a lot easier to quickly access. My hope was that the prolonged stormy weather we've had for a couple of weeks now would have brought up some nice finds, and I wasn't disappointed. Walking along the shingle I quickly spotted a worn mammal vertebra sticking out of the sand, then a couple of metres away in an area of mud was the distal end of an anthracothere humerus. Pieces like these can be pretty rare finds so I was really pleased with them. They both seem likely to be from Bothriodon based off their larger size. Moving further along the coast the productivity dropped and the finds were the usual fish vertebrae, alligator scutes, and Emys fragments punctuated by the occasional piece of rolled bone. I checked the surface of the log bed and any shelly horizon for bones or teeth that may be weathering out, but unfortunately no luck there. An interesting sight though was the log bed's huge tree trunks. Usually obscured by sand the log bed marks the boundary between the Upper and Lower Hamstead Members. It correlates with a eustatic lowstand attributed to the onset of antarctic glaciation and rapid global cooling. Around this bed is where the mammal fauna at Bouldnor passes through the famous Grande Coupure, marking the extinction of earlier endemic Eocene mammals like palaeotheres and anoplotheres, who are replaced with rhinocerotids, carnivorans, and a wide range of artiodactyls and rodents, including entelodonts and anthracotheres. The log bed represents a large log jam in fluvial swampy conditions, intermixed with the trees were the carcasses of mammals (a nearly intact Anoplotherium skeleton eroded out of the bed between the 1960's and 2002). Large tree trunks of pines and redwoods can be seen weathering out on the foreshore, and look pretty impressive. There's a long hiatus after the log bed, before the deposition of the Upper Hamstead Member above. Having passed the log bed, productivity picked up again and within the space of around 20 metres I made some pretty nice finds, including teeth from Bothriodont anthacotheres, an alligator tooth, a large section of trionychid costal plate, alligator jaw fragments, and a large cervical vertebra from an alligator (Diplocynodon sp.). Despite missing the neural arch and cervical ribs on one side the vertebra is quite well preserved and unworn, and is definitely one of the best bones I've collected from the Bouldnor Fm. I walked on a bit further towards Cranmore but decided to turn back as the tide has begun to turn. Overall, it was a great trip with some really nice finds. I'm planning on heading up to Hamstead for a full day of collecting on Saturday so I'll post on how that trip goes. Thank you, Theo 1. Worn Bothriodon vertebra 2. Distal anthracothere humerus, most likely Bothriodon 3. Diplocynodon cervical vertebra 4. Front view of the Diplocynodon vertebra
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This small crocodilian fossil was collected on the beach at Bouldnor on the Isle of Wight in southern England. It comes from the Bouldnor Formation and is about 33 million years old. I'm certain it is crocodilian (from the small aligatorid Diplocynodon) based on the distinctive pitted texture. Scutes and vertebrae from this small croc are fairly common finds on this coastline. However this particular piece has stumped me, it is 3D and hollow on the inside, not like any scute i've picked up. I was thinking it must be some sort of skull element but i'd appreciate any help to rectify this! It measures 4 cm long.
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Poebrotherium4 Single Teeth - Early Camel Fossil 1.jpg
Dpaul7 posted a gallery image in Member Collections
From the album: MY FOSSIL Collection - Dpaul7
Poebrotherium- 4 Single Teeth - Early Camel Fossil SITE LOCATION: White River Badlands, Pennington Co., South Dakota, USA TIME PERIOD: Oligocene (30 million years ago) Data: Poebrotherium is an extinct genus of terrestrial herbivore of the family Camelidae, endemic to North America from the Eocene through the Oligocene, 38—30.8 mya, thus having existed for approximately 7.2 million years. The discovery of the early camel Poebrotherium in the White River Badlands was initially puzzling. Few complete remains were found and nobody expected to find such a primitive camel in North America. Ultimately it was determined that camels first appeared in North America during the Unitan NALMA of the middle Eocene. Their expansion during the late Eocene coincided with a drying trend that produced the first areas of grassless savanna in North America. The limb morphology of Poebrotherium includes very elongate axial metapodials, reduced lateral metapodials and sharp ungual phalanges that suggests early camels were adapted to a cursorial existence in more open habitats. Unlike living camelids which are digitigrade and have padded feet, Poebrotherium was unguligrade and its ungual phalanges probably bore deer-like hooves. Early camels were lightly built and resembled modern llamas. Only two feet tall, perhaps 50 lb in weight and without any derived features, their eyes were located farther back in the skull when compared with those of modern camels. Their ribs were also much lighter. Poebrotherium had a split toe, a variation which would later evolve into a pad underneath these toes that is still seen in modern camels. Poebrotherium teeth are less hypsodont and more primitive than any other camelid except Poebrodon. They are small and have a hollow triangular cross-section which later evolved into more distinct dental variations adapted for plucking and grinding vegetation Teeth toward the front of the jaw are reduced in size and peg-like. The skull of Poebrotherium is approximately7 inches long and constructed of thin fragile bones. Because camel skulls are narrow and elongated, most have broken cheekbones and orbits when found and complete skulls are a rare find. Compared to other herbivores, camelids are relatively rare in the Eocene. This did not change until after the Chadronian NALMA when the remains of Poebrotherium wilsoni, the gazelle-camel, became abundant in the White River deposits of Colorado and southeastern Wyoming and although camel remains are more common in Nebraska and eastern Wyoming than in South Dakota, their remains are still rarer than those of oreodonts. Living camelids from South America, including vicuna and guanacos as well as the domesticated alpaca and llama, do not have humps and probably resemble the early camels of the White River beds. Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Artiodactyla Family: Camelidae Genus: †Poebrotherium Species: †wilsoni -
Poebrotherium4 Single Teeth - Early Camel Fossil 1.jpg
Dpaul7 posted a gallery image in Member Collections
From the album: MY FOSSIL Collection - Dpaul7
Poebrotherium- 4 Single Teeth - Early Camel Fossil SITE LOCATION: White River Badlands, Pennington Co., South Dakota, USA TIME PERIOD: Oligocene (30 million years ago) Data: Poebrotherium is an extinct genus of terrestrial herbivore of the family Camelidae, endemic to North America from the Eocene through the Oligocene, 38—30.8 mya, thus having existed for approximately 7.2 million years. The discovery of the early camel Poebrotherium in the White River Badlands was initially puzzling. Few complete remains were found and nobody expected to find such a primitive camel in North America. Ultimately it was determined that camels first appeared in North America during the Unitan NALMA of the middle Eocene. Their expansion during the late Eocene coincided with a drying trend that produced the first areas of grassless savanna in North America. The limb morphology of Poebrotherium includes very elongate axial metapodials, reduced lateral metapodials and sharp ungual phalanges that suggests early camels were adapted to a cursorial existence in more open habitats. Unlike living camelids which are digitigrade and have padded feet, Poebrotherium was unguligrade and its ungual phalanges probably bore deer-like hooves. Early camels were lightly built and resembled modern llamas. Only two feet tall, perhaps 50 lb in weight and without any derived features, their eyes were located farther back in the skull when compared with those of modern camels. Their ribs were also much lighter. Poebrotherium had a split toe, a variation which would later evolve into a pad underneath these toes that is still seen in modern camels. Poebrotherium teeth are less hypsodont and more primitive than any other camelid except Poebrodon. They are small and have a hollow triangular cross-section which later evolved into more distinct dental variations adapted for plucking and grinding vegetation Teeth toward the front of the jaw are reduced in size and peg-like. The skull of Poebrotherium is approximately7 inches long and constructed of thin fragile bones. Because camel skulls are narrow and elongated, most have broken cheekbones and orbits when found and complete skulls are a rare find. Compared to other herbivores, camelids are relatively rare in the Eocene. This did not change until after the Chadronian NALMA when the remains of Poebrotherium wilsoni, the gazelle-camel, became abundant in the White River deposits of Colorado and southeastern Wyoming and although camel remains are more common in Nebraska and eastern Wyoming than in South Dakota, their remains are still rarer than those of oreodonts. Living camelids from South America, including vicuna and guanacos as well as the domesticated alpaca and llama, do not have humps and probably resemble the early camels of the White River beds. Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Artiodactyla Family: Camelidae Genus: †Poebrotherium Species: †wilsoni -
From the album: Decapoda
14cm. Shows the underside. Prepared out of a concretion found on the beach at Mogenstrup, Limfjord, Denmark. Oligocene, Chatt B, Vejle Fjord Formation. -
Well, This is a story that tangentially relates to fossil excursions. I'm not one to want to collect jars of shards or Leaverites but I do like to pocket teeth that I think would be good for trades , gifts etc. My son is approaching the age now where he shows a bit more interest and he has started many 'collections' , shark teeth being one of many. (he collects rocks, sticks, bugs, buttons, shiny crystals - more rocks-, you get the idea) I visited his school this morning for my first (hopefully one of many) presentations. I had a few visual aids up on the projector screen but mainly talked about the Oligocene of South Carolina and sharks. Well, ok Megalodon sharks and the things that they ate, and the landscape at the time. 20 minutes was about all that these figit-y pre-k and kindergarten kids would give me but it was worth it. I may have converted a few in the process. Of course images of fossilized poo won the day and got the biggest reaction. Go figure ... though, I did stick those images in for that very reason. I'd like to give a shout out to Bobby @Boesse and the Mace Brown Museum of Natural History in Charleston for the inspiration. The exhibits there are outstanding and really give you a nice slice of the fauna in the area at the time. I relied on shots from inside of the museum for visual aids when discussing Basilosaurids and the evolution of whales (the kids honestly were more impressed with the whale's teeth). And if it wasn't for Cade and his most excellent hand-drawn identification page @Sharks of SC I don't think the visuals would have been half as impressive. The kids loved the handouts Cade and the cool thing is they double as something that they can color ! The prep Goodie bags for 22 students. They each got 5 teeth from 4 different sharks. Angy partials Oh, and if you are curious the meg at the far end of the table is a beautiful 7" inch reproduction of a Meg tooth by Matty Swilp. One the kids could handle and toss around without me having a heart attack. It looks amazing. The 7 inch repro ... Cheers, Brett
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I was wondering if anyone could help ID two strange parts of this partial Leptauchenia fossilised skeleton. I've been prepping the bones out of the matrix (which is only a 15%-20% skeleton), but the skull is incredibly complete with all teeth. I've put a photo showing the bones I've identified against a reconstruction by Sinclair in 1910, but there are two strange objects I can't ID. These are of a texture that look more like teeth (than bones) and even seems to have some enamel-type gloss. They are more "claw-shaped" however and the skull isn't missing any teeth which is why I'm confused. The high gloss, smooth finish is whats confusing me. Any help would be greatly appreciated.
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