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Wednesday, November 6th, 2024
| Time | Event | ||||||
| 12:10a | [Paleontology • 2024] Extremely rapid, yet noncatastrophic, Preservation of the Flattened-feathered and 3D Dinosaurs of the Early Cretaceous of China
Significance: Traditionally, the spectacular preservation of fossils of feathered dinosaurs and early birds and other animals found in sedimentary strata of the Yixian Formation in northeast China has been attributed to Pompeii-like volcanic catastrophes. We provide high-resolution geochronology and sedimentological analysis challenging this model and show that these strata instead record normal life and death processes preserved in a succession of depositional environments that span less than 100 thousand years. Abstract Northeast China’s Early Cretaceous Yixian Formation preserves spectacular fossils that have proved extraordinarily important in testing evolutionary hypotheses involving the origin of birds and the distribution of feathers among nonavian dinosaurs. These fossils occur either flattened with soft tissue preservation (including feathers and color) in laminated lacustrine strata or as three-dimensional (3D) skeletons in “life-like” postures in more massive deposits. The relationships of these deposits to each other, their absolute ages, and the origin of the extraordinary fossil preservation have been vigorously debated for nearly a half century, with the prevailing view being that preservation was linked to violent volcanic eruptions or lahars, similar to processes that preserved human remains at Pompeii. We present high-precision zircon U-Pb geochronology from cores and outcrops, demonstrating that Yixian Formation accumulation rates are more than an order of magnitude higher than usually estimated. Additionally, we provide zircon provenance and sedimentological data from 3D dinosaur fossils, which imply that their death and burial occurred in collapsed burrows, rather than via a catastrophic volcanogenic mechanism. In the studied area, the three principal fossil-rich intervals of the Yixian occur as a cyclic sequence that correspond to periods of high precipitation. Using Bayesian–Markov Chain Monte Carlo approaches, we constrain the total duration of the sequence to less than ~93,000 y and suggest that climatic precession paced the expression of these cyclic sediments. Rather than representing multiple, Pompeii-like catastrophes, the Yixian Formation is instead a brief snapshot of normal life and death in an Early Cretaceous continental community.
Scott A. MacLennan, Jingeng Sha, Paul E. Olsen, Sean T. Kinney, Clara Chang, Yanan Fang, Jun Liu, Bennett B. Slibeck, Elaine Chen, and Blair Schoene. 2024. Extremely rapid, yet noncatastrophic, Preservation of the Flattened-feathered and 3D Dinosaurs of the Early Cretaceous of China. PNAS. 121 (47) e2322875121. DOI: doi.org/10.1073/pnas.2322875121 | ||||||
| 9:00a | [Ichthyology • 2024] Vexillichthys gen. nov. • A New Genus for the Blackfin Sucker, Thoburnia atripinnis (Cypriniformes: Catostomidae)
Abstract Thoburnia atripinnis is more closely related to Hypentelium (hogsuckers) than it is to other Thoburnia, and its presence in the Barren River of Kentucky is disjunct from that of true Thoburnia. Its unique morphology is unlike that of the easily recognized hogsuckers, making placement of the species within Hypentelium untenable; thus, a new genus is described. The new genus can be separated from all other catostomids by the presence of thin, black, prominent stripes on the body, a large black mark on the anterodist al portion of the dorsal fin, presence of pads ventrally on the leading portion of the pectoral fin, lateral laminae of the dermethmoid angled anteriorly, and the base of the lateral ethmoid narrow. Pisces, Hypentelium, Moxostoma, Thoburnini, Taxonomy
Vexillichthys Armbruster, new genus Type species. Moxostoma (Thoburnia) atripinne Bailey 1959 Diagnosis. Vexillichthys can be separated from all other Catostomids by the presence of well-developed, thin, black stripes on the body and a large, black mark on the anterodistal portion of the dorsal fin. Members of Hypentelium and Thoburnia may have stripes, but the stripes are faint, and the dorsal saddles are darker than the stripes (vs. the stripes darker than the saddles in Vexillichthys). Hypentelium does have dark marks in the dorsal fin, but the fin has bands or blotches instead of a single, large, black area at the anterodistal portion of the fin and the remainder of the fin hyaline. Vexillichthys can be further separated from Thoburnia by lacking a rust-colored, wide lateral stripe. Minytrema also has dark stripes, but these are composed of distinct ... Etymology. From the Latin vexillum for flag and the Greek ichthys for fish. The dorsal fin has a flaglike pattern and the approximately thirteen alternating dark and light stripes are like the flag of the United States of America. Gender masculine. Jonathan W. ARMBRUSTER. 2024. A New Genus for the Blackfin Sucker, Thoburnia atripinnis (Cypriniformes: Catostomidae). Zootaxa. 5536(2); 325-335. DOI: doi.org/10.11646/zootaxa.5536.2.8  | ||||||
| 9:12a | [Botany • 2022] Curcuma lampangensis & C. sabhasrii (Curcuma subg. Ecomatae, Zingiberaceae: Zingibereae) • Two New Species from northern Thailand
Abstract Curcuma lampangensis Saensouk, Maknoi & Rakarcha and C. sabhasrii Saensouk, Maknoi, Wongnak & Rakarcha, two new species of ginger family (Zingiberaceae) from northern Thailand, are described, illustrated and photographed. Additionally, the authors provide their detailed morphological descriptions, as well as illustrations, color photographs, distributions, ecology, etymology, phenology, vernacular, conservation status and its closely related species. The two new species are assignable to the Curcuma subgenus Ecomatae. Curcuma lampangensis and C. sabhasrii are endemic to Lampang and Phitsanulok provinces of northern Thailand, respectively. The morphological characteristics of C. lampangensis are compared to C. rhomba J. Mood & K. Larsen while C. sabhasrii is compared to C. peramoena Souvann. & Maknoi. Curcuma lampangensis is recognized by its glabrous on nearly all parts of the plant, creeping rhizome and the inflorescence usually arises from a new rhizome branch next to the existing pseudostem, flowers that are white to pale pink and white to pale yellow labellum with 2 dark yellow bands at the center and reddish tinge at the base. Curcuma sabhasrii is recognized by having 8-15 greenish to reddish-purple bracts, reddish-purple corolla lobes, white with reddish-purple mottling to reddish-purple staminodes and labellum which is reddish-purple with an embossed yellow path along the midrib from base to apex and reddish-purple mottling on yellow mid-band of lower half. A key to 24 species of Curcuma subgenus Ecomatae in Thailand is presented.
Curcuma lampangensis Saensouk, Maknoi & Rakarcha กระเจียวลำปาง Curcuma sabhasrii Saensouk, Maknoi, Wongnak & Rakarcha, กระเจียวสรรพศรี Sarayut Rakarcha, Surapon Saensouk, Charun Maknoi, Mathee Wongnak, Woranart Thammarong and Piyaporn Saensouk. 2022. Curcuma lampangensis and C. sabhasrii, Two New Species of the Family Zingiberaceae from northern Thailand. Biodiversitas. 23: 4448-4459. https://smujo.id/biodiv/article/view/11720 | ||||||
| 1:16p | [Herpetology • 2024] Cyrtodactylus mamberamo • A New Species of Narrow-banded Cyrtodactylus (Gekkonidae) from northern New Guinea
Abstract We describe a new species of Cyrtodactylus from the northern lowlands and foothills of mainland New Guinea. Cyrtodactylus mamberamo sp. nov. is distinguished from all other Melanesian Cyrtodactylus except C. aaroni and C. mimikanus by the combination of moderate size (max SVL <100 mm), widened subcaudals, dorsal pattern of numerous narrow light bands with dark-brown anterior borders, and a tripartite pore arrangement in males. It differs from these two most-similar species in details of colour pattern, scalation and the number of precloacal pores. Cyrtodactylus mamberamo sp. nov. occurs at elevations between 0–870 m above sea level (a.s.l.) across a wide area spanning the Mamberamo Basin and nearby regions. It co-occurs with at most one or two other congeners. Low Cyrtodactylus alpha diversity across Melanesia emphasises beta turnover as the key factor underpinning species richness in this genus. The new species brings the total number of recognised Melanesian Cyrtodactylus to 35, with the real total certain to be over 40 species. Reptilia, Cyrtodactylus mimikanus, Indonesia, Mamberamo Basin, Papua New Guinea
Cyrtodactylus mamberamo sp. nov. Mamberamo Basin Bent-toed Gecko Paul M. Oliver, Nicholas Boothroyd, Burhan Tjaturadi, Awal Riyanto, Djoko T. Iskandar and Stephen J. Richards. 2024. A New Species of Narrow-banded Cyrtodactylus (Gekkonidae) from northern New Guinea. Zootaxa. 5506(1); 79-92. DOI: doi.org/10.11646/zootaxa.5506.1.4 generasibiologi.com/2024/10/cyrtodactylus-mamberamo-spe Researchgate.net/publication/384201786_A https://zenodo.org/records/13746582 https://photos.chienclee.com/image/I0000 | ||||||
| 1:25p | [PaleoMammalogy • 2024] Romaleodelphis pollerspoecki • An archaic Dolphin from the Central Paratethys (Early Miocene, Austria)
ABSTRACT A new long-snouted homodont odontocete fossil from the Lower Miocene of Austria (ca. 22.5–22.0 Ma) is formally described and interpreted based on external skull characteristics supplemented by CT and µCT data. The specimen was found in deposits from the Central Paratethys and includes an incomplete and fragmented cranium and mandible as well as ear bones. It differs markedly from previously identified long-snouted archaic dolphins with single-rooted, homodont dentition, and thus is suggestive of a new taxon, for which the name Romaleodelphis pollerspoecki proposed. The geological context of R. pollerspoecki hints at a neritic habitat in close vicinity to estuarine environments. Romaleodelphis pollerspoecki shares key features with certain members of the so-called ‘Chilcacetus clade’ such as the widening of the premaxillae at the rostrum base and the absence of a deep lateral groove along the rostrum; however, a phylogenetic analysis reconstructs R. pollerspoecki in a polytomy with members of this ‘clade’ and a larger clade including many other taxa. To better understand the phylogenetic relationships of these taxa, comprehensive reexamination of Argryocetus and Macrodelphinus will be necessary. Measurements obtained through µCT-based internal anatomical reconstruction of the bony labyrinth indicate that R. pollerspoecki had the ability to hear specialized high-frequency signals similar to modern narrow-band high-frequency (NBHF) specialists. This work further identifies several extinct platanistoids as hearing within the NBHF spectrum, increasing the understanding of the diversity of ecological adaptations in early-diverging odontocetes and providing more examples of convergent evolution of this hearing type.   Romaleodelphis pollerspoecki, gen. et sp. nov.  Catalina Sanchez-Posada, Rachel A. Racicot, Irina Ruf, Michael Krings and Gertrud E. Rössner. 2024. Romaleodelphis pollerspoecki, gen. et sp. nov., An archaic Dolphin from the Central Paratethys (Early Miocene, Austria). Journal of Vertebrate Paleontology. e2401503. DOI: doi.org/10.1080/02724634.2024.2401503 Archaic dolphin could hear high frequency sounds |
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