Petrified Forest National Park

Forest, AZ, United States

Petrified Forest National Park

Forest, AZ, United States

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News Article | May 10, 2017
Site: www.scientificamerican.com

Dinosaurs are our ambassadors to the deep past. There’s hardly a better example of this fact than the Triassic. This stretch of time, the first chapter of the three-part Mesozoic epic, is often referred to as the Dawn of the Dinosaurs and ran from about 250 to 200 million years ago. This is despite the fact that dinosaurs were minor players in the Triassic drama. Sure, the first dinosaurs evolved by about 235 million years ago, but they were small and ecologically marginal animals for most of the period. The true rulers of the Triassic world were stranger creatures, many of them more closely related to crocodiles, and we are only just now becoming acquainted with the various species that we’ve let dinosaurs overshadow. The Triassic menagerie is far weirder than previous generations of paleontologists expected, and it’s only set to get more bizarre. Consider Kraterokheirodon. Nobody knows what Kraterokheriodon is. The nature of this animal is totally inscrutable, joining the ranks of species like the Tully Monster in the ranks of fossil Problematica. But the two fossil teeth that represent this animal signal that there was something very odd shuffling around the Late Triassic of Arizona. Paleontologists Randall Irmis and William Parker, who named Kraterokheriodon in 2005, followed the fossil trail as far as they could. The story of the “cupped hand tooth” started in 1946. It was in that year that geologist G.E. Hazen found an unusual tooth from the Triassic Chinle Formation of Arizona and gave the tooth to paleontologist Edwin Colbert. It was unlike any fossil found before, having a curved, shell-like shape. And that’s as far as the story of the tooth went until 1984, when Lynette Gillette found a similar tooth in Petrified Forest National Park. This was enough to reignite Colbert’s interest, although he couldn’t confidently assign the teeth to any known group. He was still studying them when he passed away in 2001. Paleontologists Robert Long and Phillip Murry had an idea about who those teeth originally belonged to. In a 1995 paper, they proposed that the strange teeth were those of herbivorous protomammals called traversodont cynodonts. That’s why these animals had such a big role in the Petrified Forest episode of Walking With Dinosaurs. But Irmis and Parker didn’t find any direct support for this idea in their analysis of the fossil. (Hazen’s initial find is now only known as a cast, with the original missing, making Gillette’s find the only existing specimen.) The furthest they were able to narrow their identification of Kraterokheriodon colberti was Amniota, the major group that includes mammals, reptiles, and their closest relatives. Kraterokheirodon is so bizarre, Irmis and Parker explained, that it’s difficult to understand how the unusual teeth even fit into the animal’s mouth. The fossils definitely are teeth – there’s enamel, dentine, a root, and other details which confirm this – but the certainties don’t go much further than that. The teeth don’t resemble those of lungfish, bony fish, or amphibians. And while the Kraterokheriodon teeth somewhat resemble those of some cynodonts, Irmis and Parker wrote, they are far larger and the superficial similarities may be a case of convergence rather than family relationships. Ultimately, Irmis and Parker concluded, “the recognition of these teeth as a new and unique taxon is a reminder of how little is still known about the fauna of the Late Triassic Period.” That’s certainly understating how frustrating the lack of additional material has been. Based upon the size of the teeth, Kraterokheriodon must have been a large animal. This was not a small, delicate creature unlikely to fossilize. This was an animal that should have had similar fossilization potential to the phytosaurs, aetosaurs, dinosaurs, and other big-bodied fauna of Arizona’s Late Triassic. So where is it? The experts who explore the Petrified Forest continually ask themselves that question as they wander out into the Painted Desert. Somewhere out there, the key to Kraterokheriodon is waiting. This post was supported by my generous backers on Patreon. For details on how you can get an early view of new blog posts and exclusive natural history essays, click here. Irmis, R., Parker, W. 2005. Unusual tetrapod teeth from the Upper Triassic Chinle Formation, Arizona, USA. Canadian Journal of Earth Sciences. doi: 10.1139/e05-031


Reichgelt T.,University Utrecht | Parker W.G.,Petrified Forest National Park | Parker W.G.,University of Texas at Austin | Martz J.W.,Petrified Forest National Park | And 3 more authors.
Review of Palaeobotany and Palynology | Year: 2013

Recent paleontological investigations and lithostratigraphic revisions reveal a marked biotic turnover zone within the continental deposits of the Sonsela member of the Chinle Formation (Late Triassic, Norian) at Petrified Forest National Park, USA.Within the Sonsela member we found three pollen assemblage biozones: Zone II (90.5-94. m above the Mesa Redondo member) contains a relatively diverse palynological assemblage, with a mix of pteridosperms, voltzialean and some Mesozoic conifers. Following a 2.3. m hiatus, Zone IIIa (96-97.5. m) is characterized by a decrease in pteridosperms and Mesozoic conifers and a drop in voltzialean conifer diversity. The alleged voltzialean conifer pollen Klausipollenites gouldii was dominant in this part of the assemblage and a significant rise in spores and cycad pollen was also evident. In Zone IIIb (97.5-98.5. m) diversity increases and several taxa, which were absent in Zone IIIa reappear, although K. gouldii remained the most abundant taxon. The transition between the palynological assemblages Zones II and IIIa coincide approximately (within a ~. 2.5. m interval) with a documented faunal turnover.The floristic assemblages suggest that the climate of the south-western United States during the Norian was most likely semi-arid and highly seasonal, despite being located at tropical latitudes, with aridification occurring towards the end-Triassic as the continent drifted northwards and global volcanism increased. The gymnosperm-dominated palynofloral assemblage as opposed to the fern- and horsetail-dominated macrofossil record of the Sonsela member of the Chinle Formation, conforms to a semi-arid upland environment alternated by riparian, swampy lowland. © 2012 Elsevier B.V.


Parker W.G.,Petrified Forest National Park | Parker W.G.,University of Texas at Austin | Hungerbuhler A.,Mesalands Community College | Martz J.W.,Denver Museum of Nature and Science
Earth and Environmental Science Transactions of the Royal Society of Edinburgh | Year: 2013

The genus Machaeroprosopus has long been considered invalid because the type specimen of the Late Triassic phytosaur species, M. validus, has been lost. Re-examination of the primary literature regarding the establishment of the Late Triassic phytosaur genus Machaeroprosopus demonstrates that M. buceros is the correct type species, not M. validus. Thus, the genus level name Machaeroprosopus has priority over the genera Pseudopalatus and Arribasuchus and all nominal species should be reassigned. Reassignment of these species to Machaeroprosopus satisfies the requirements of the International Code of Zoological Nomenclature (ICZN) and preserves historical context. The name Pseudopalatinae is retained as the valid clade name for these phytosaurs because its usage falls outside of the ICZN. © 2013 The Royal Society of Edinburgh.


News Article | December 16, 2016
Site: motherboard.vice.com

Few places are as steeped in mythology as the Hawaiian Islands. And as an archipelago literally borne out of fire, one of Hawaiʻi's most famous legends is that of Pele, or Pelehonuamea, the charismatic volcano goddess. Sometime during 20th century, a false but pervasive superstition regarding Pele's "cursed rocks" began to creep around Hawaiʻi's national parks, especially those with active volcanoes. The story goes that if a rock, or even grain of sand, is taken from Pele's domain, a curse will fall upon you. As a result, hundreds of stolen items are allegedly returned to the National Park Service each year by people frightened of Pele's comeuppance. Over the last several decades, Pele's name has been corrupted by the tourism industry, according to National Park Service records obtained by Motherboard through a Freedom of Information Act request. "There is NO 'Curse of the Rocks,'" a cultural interpreter for the National Park Service wrote in a document that was circulated internally. "Many believe that the idea of lava rocks being cursed gained traction in the 1940s or 1950s when tour guides grew tired of cleaning their vehicles of lava and/or black sand after tours to Kalapana [a popular destination on the island of Hawaiʻi for viewing active lava flows]." While the cautionary tale might seem harmless—even staving off klepto behavior (I grew up in Hawaiʻi and remember being warned about Pele's intolerance for thieves)—some residents loathe the myth for being culturally appropriative—an "ethnic" story that fits with outsiders' desires to test the will of gods with whom they have no connection. As such, National Park Service staff seem eager to put out the fire, so to speak. "You know, in Native Hawaiian oli [chants], hula, or mele [songs], there's no saying that Pele would curse you if you took a rock from Kilauea or anywhere else," Jessica Ferracane, a public affairs specialist for Hawaiʻi Volcanoes National Park, told me. In an email to a USA Today reporter regarding a story on Hawaiʻi Volcanoes National Park, Ferracane referred to the superstition as "deeply offensive" to the islands' indigenous community. The senior director of communications at the Hawaiʻi Visitors and Convention Bureau, Darlene Morikawa, later wrote to Ferracane that she's heard the tale so often, she's become "numb" to reading about it. It's true that Native Hawaiian history makes no mention of Pele's penchant for punishing pilferers. While there are many parables about her mercurial ways—according to legend, she once killed the friend of her sister Hiʻiaka for taking too long to run an errand—the goddess never had it out for greedy tourists. Still, taking items or artifacts from national parks is against the law. "There are actual federal laws not to remove, tamper with, or destroy natural resources," Ferracane said. Curiously, cursed rocks aren't unique to Hawaiʻi, either. A similar phenomenon has been plaguing Arizona's Petrified Forest National Park for decades, according to Ryan Thompson and Phil Orr who wrote Bad Luck, Hot Rocks: Conscience Letters and Photographs From the Petrified Forest. Sifting through the national park's archives, Thompson and Orr discovered letters from hundreds of apologetic visitors, desperate to rid themselves of the contraband that supposedly caused the death of their cat, their broken down car, or a trip to the emergency room. There's some speculation among National Park Service staff that "tabloid" stories are responsible for keeping the myth alive. (Just last week, dozens of outlets wrote about Jennifer Lawrence's unfortunate desecration of sacred, "cursed" stones while filming The Hunger Games: Catching Fire on Maui.) While it's probably a good idea to send rocks back to where they came from, some online citizens offer an intermediary return service (for a voluntary donation), proudly publishing customers' remorseful stories on their website. As a result, Hawaiʻi's national parks are constantly fielding returned items and guilty consciences. Letters addressed to Hawaiʻi Volcanoes National Park are received daily, while repatriated rocks arrive at least once per week, according to Ferrante. Even local post offices receive stolen stones, sometimes simply addressed to "postmaster." In 2015, the Hawaiian Islands saw 8.6 million visitors, according to the Hawaiʻi Tourism Authority. The fierce splendor of Hawaiʻi's still-active volcanoes attracted 1.6 million visitors to Hawaiʻi Volcanoes National Park in 2013, generating some $113,376,400 in revenue for surrounding business. Ultimately, the apocryphal story of Pele's curse is unlikely to go away anytime soon. But if there's one thing that people like Ferracane want, it's for tourists to explore the authentic side of Native Hawaiian culture. "[The superstition] wasn't started in a mean way. But here, people are told that taking pohaku [stones] is a sign of disrespect. You wouldn't take something that doesn't belong to you from somebody's house," she added. Get six of our favorite Motherboard stories every day by signing up for our newsletter.


Parker W.G.,University of Texas at Austin | Martz J.W.,Petrified Forest National Park
Earth and Environmental Science Transactions of the Royal Society of Edinburgh | Year: 2010

Recent stratigraphic revisions of the Upper Triassic Chinle Formation of Petrified Forest National Park, in conjunction with precise and accurate documentation of fossil tetrapod occurrences, clarified the local biostratigraphy, with regional and global implications. A significant overlap between Adamanian and Revueltian faunas is rejected, as is the validity of the Lamyan sub-land vertebrate faunachron. The Adamanian-Revueltian boundary can be precisely placed within the lower Jim Camp Wash beds of the Sonsela Member and thus does not occur at the hypothesised Tr-4 unconformity. This mid-Norian faunal turnover, may coincide with a floral turnover, based on palynology studies and also on sedimentological evidence of increasing aridity. Available age constraints bracketing the turnover horizon are consistent with the age of the Manicouagan impact event. The rise of dinosaurs in western North America did not correspond to the Adamanian-Revueltian transition, and overall dinosauromorph diversity seems to have remained at a constant level across it. The paucity of detailed Late Triassic vertebrate biostratigraphic data and radioisotopic dates makes it currently impossible to either support or reject the existence of globally synchronous Late Triassic extinctions for tetrapods. © 2011 The Royal Society of Edinburgh.


Parker W.G.,Petrified Forest National Park | Parker W.G.,University of Texas at Austin
Earth and Environmental Science Transactions of the Royal Society of Edinburgh | Year: 2013

Historic type and referred material of the aetosaurian taxa Typothorax coccinarum, Episcoposaurus horridus and Episcoposaurus haplocerus are redescribed and the non-aetosaurian material identified and removed, a task previously considered hopeless. Reexamination of the original material reveals that the holotypes of E. haplocerus and probably T. coccinarum are not diagnosable at the species level and therefore are nomena dubia. The next available names for material referred to these taxa are Desmatosuchus spurensis and E. horridus respectively, although it may be more desirable for reasons of taxonomic stability to attempt to petition for a neotype in the latter case. The redescription of historical specimens is necessary to determine their nomenclatural validity. The use of referred specimens as proxy type specimens is problematic, as these referrals were originally made not on the basis of apomorphies, but rather on biostratigraphic and/or geographical assumptions which are inherently circular and cannot be unambiguously supported. © 2013 The Royal Society of Edinburgh.


Desojo J.B.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Heckert A.B.,Appalachian State University | Martz J.W.,Denver Museum of Nature and Science | Parker W.G.,Petrified Forest National Park | And 4 more authors.
Geological Society Special Publication | Year: 2013

Aetosauria is a clade of obligately quadrupedal, heavily armoured pseudosuchians known from Upper Triassic (late Carnian-Rhaetian) strata on every modern continent except Australia and Antarctica. As many as 22 genera and 26 species ranging from 1 to 6 m in ength, and with a body mass ranging from less than 10 to more than 500 kg, are known. Aetosauroides scagliai was recently recovered as the most basal aetosaur, placed outside of Stagonolepididae(the last common ancestor of Desmatosuchus and Aetosaurus). Interrelationships among the basal aetosaurs are not well understood but two clades with relatively apomorphic armour-the spinose Desmatosuchinae and the generally wide-bodied Typothoracisinae-are consistently ecognized. Paramedian and lateral osteoderms are often distinctive at the generic level but variation within the carapace is not well understood in many taxa, warranting caution in assigning isolated osteoderms to specific taxa. The aetosaur skull and dentition varies across taxa, and there is increasing evidence that at least some aetosaurs relied on invertebrates and/or small vertebrates s a food source. Histological evidence indicates that, after an initial period of rapid growth, lines of arrested growth (LAGs) are common and later growth was relatively slow. The common and widespread Late Triassic ichnogenus Brachychirotherium probably represents the track of an aetosaur. © The Geological Society of London 2013.


Recent revisions to the Sonsela Member of the Chinle Formation in Petrified Forest National Park have presented a three-part lithostratigraphic model based on unconventional correlations of sandstone beds. As a vertebrate faunal transition is recorded within this stratigraphic interval, these correlations, and the purported existence of a depositional hiatus (the Tr-4 unconformity) at about the same level, must be carefully re-examined.Our investigations demonstrate the neglected necessity of walking out contacts and mapping when constructing lithostratigraphic models, and providing UTM coordinates and labeled photographs for all measured sections. We correct correlation errors within the Sonsela Member, demonstrate that there are multiple Flattops One sandstones, all of which are higher than the traditional Sonsela sandstone bed, that the Sonsela sandstone bed and Rainbow Forest Bed are equivalent, that the Rainbow Forest Bed is higher than the sandstones at the base of Blue Mesa and Agate Mesa, that strata formerly assigned to the Jim Camp Wash beds occur at two stratigraphic levels, and that there are multiple persistent silcrete horizons within the Sonsela Member.We present a revised five-part model for the Sonsela Member. The units from lowest to highest are: the Camp Butte beds, Lots Wife beds, Jasper Forest bed (the Sonsela sandstone)/Rainbow Forest Bed, Jim Camp Wash beds, and Marthas Butte beds (including the Flattops One sandstones). Although there are numerous degradational/aggradational cycles within the Chinle Formation, a single unconformable horizon within or at the base of the Sonsela Member that can be traced across the entire western United States (the Tr-4 unconformity) probably does not exist. The shift from relatively humid and poorly-drained to arid and well-drained climatic conditions began during deposition of the Sonsela Member (low in the Jim Camp Wash beds), well after the Carnian-Norian transition.

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