Monday, 27 July 2020
HOMARUS KARELSNSIS: LOBSTER FROM LEBANON
The Cape lobster, which was formerly in this genus as H. capensis, was moved in 1995 to the new genus Homarinus.
Lobsters have long bodies with muscular tails and live in crevices or burrows on the seafloor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others.
Highly prized as seafood, lobsters are economically important and are often one of the most profitable commodities in coastal areas they populate. Commercially important species include two species of Homarus — which looks more like the stereotypical lobster — from the northern Atlantic Ocean, and scampi — which looks more like a shrimp — the Northern Hemisphere genus Nephrops and the Southern Hemisphere genus Metanephrops. Although several other groups of crustaceans have the word "lobster" in their names, the unqualified term lobster generally refers to the clawed lobsters of the family Nephropidae.
Clawed lobsters are not closely related to spiny lobsters or slipper lobsters, which have no claws or chelae, or to squat lobsters. The closest living relatives of clawed lobsters are the reef lobsters and the three families of freshwater crayfish. This cutie was found in Cretaceous outcrops at Hâdjoula. The sub‐lithographical limestones of Hâqel and Hâdjoula, in north‐west Lebanon, produce beautifully preserved shrimp, fish, and octopus. The localities are about 15 km apart, 45 km away from Beirut and 15 km away from the coastal city of Jbail.
Sunday, 26 July 2020
PHYLLOCERAS VELLEDAE
Friday, 24 July 2020
SULPHATES AND CLIMATE CHANGE
% of Diffusely Reflected Sunlight |
- Lewis, Gilbert N. (1916). "The Atom and the Molecule". J. Am. Chem. Soc. 38: 762–785. doi:10.1021/ja02261a002. (See page 778.)
- Pauling, Linus (1948). "The modern theory of valency". J. Chem. Soc.: 1461–1467. doi:10.1039/JR9480001461.
- Coulson, C. A. (1969). "d Electrons and Molecular Bonding". Nature. 221: 1106. Bibcode:1969Natur.221.1106C. doi:10.1038/2211106a0.
- Mitchell, K. A. R. (1969). "Use of outer d orbitals in bonding". Chem. Rev. 69: 157. doi:10.1021/cr60258a001.
Thursday, 23 July 2020
PYRITE PRESERVATION
Ammonite Preserved in Pyrite. Fossil Huntress |
Wednesday, 22 July 2020
AMMOLITE
Ammolite from the Bearpaw Formation |
Tuesday, 21 July 2020
FOSSIL PRESERVATION: REPLACEMENT
Monday, 20 July 2020
AMMONITES: CHAMBERED BEAUTY
Sunday, 19 July 2020
DINOSAURS OF THAILAND
- Ingavat, R., Janvier, R., and Taquet, P. (1978) Decouverte en Thailande d'une portion de femur de dinosaure sauropode (Saurischia, Reptilia). C.R. Soc.Geol.France 3: 140-141
- Wickanet Songtham and Benja Sektheera (2006) Phuwiangosaurus sirindhornae Bangkok: Department of Mineral Resources: 100 pages
- Buffetaut, E., Suteethorn, V., and Tong, H. (2009) An earliest 'ostrich dinosaur' (Theropoda: Ornithomosauria) from the Early Cretaceous Sao Khua Formation of NE Thailand, pp. 229-243, in E. Buffetaut, G. Cuny, J. Le Loeuff, and V. Suteethorn (eds.), Late Palaeozoic and Mesozoic Ecosystem in SE Asia. Geological Society, London, Special Publication 315.
Friday, 17 July 2020
UPPER TRIASSIC LUNING FORMATION
Thursday, 16 July 2020
PARASAUROLOPHUS WALKERI OF ALBERTA
Holotype Specimen of P. walkeri, Royal Ontario Museum |
Tuesday, 14 July 2020
HAREMS AND BLUEHEAD WRASSE
Monday, 13 July 2020
FLOUNDERS: BILATERAL SYMMETRY AND SHOOTING X'S
Sunday, 12 July 2020
CAMPANIAN OF HOKKAIDO
Saturday, 11 July 2020
MEET ANKYLORHIZA, APEX DOLPHIN
Friday, 10 July 2020
BOTTLENOSE DOLPHINS
Thursday, 9 July 2020
CERATITES NODOSUS
Wednesday, 8 July 2020
OH, CORONICERAS!
Coroniceras with a sweet, sweet keel |
Tuesday, 7 July 2020
SPOTTED CLEANER SHRIMP: FISH WASH
Thursday, 2 July 2020
HETEROPTERAN OF THE GREEN RIVER
Sunday, 28 June 2020
CRASPEDITES OF RUSSIA
Saturday, 27 June 2020
AMMONITES OF THE VOLGA REGION
The Heteromorph, Jaubertites (Audouliceras) renauxianum |
These magnificent Jaubertites (Audouliceras) renauxianum heteromorph ammonites are often composites — built with exceptional artful skill from various partial specimens.
We sometimes see them cut in two symmetrical parts and glued into a matrix then doctored up a bit for sale. The practice is frowned upon both scientifically and commercially but continues as does the demand for these exceptional specimens. This beauty is in the collection of José Juárez Ruiz and is complete with some minor restorations. I love these chunky Jaubertites and particularly appreciate the beautiful oil in water colouring in the nacre.
The second photo here shows a lovely busy block of ammonites with Deshayesites volgensis (Sasonova, 1958), and Aconeceras (Sinzovia) trautscholdi (Sinzow. 1870) from Lower Cretaceous, Aptian, (120 - 112 MYA), deposits in the v. Shilovka, Ulyanovsk Region of Russia. This beauty is in the collections of Emil Black. While Emil has counselled me that there are some fundamental challenges with the interpretation of these faunal groups, I will share what is available from the current literature.
Aptian deposits near the Volga River between Ul'yanovsk and Saratov have been studied for more than a century. The area produces some of the most beautiful and sought after ammonite specimens in the world. I've never had the pleasure of collecting in this region but follow the literature and local collectors with enthusiastic interest. Looking at the specimens from here, I'm sure you can appreciate why.
Deshayesites volgensis & Aconeceras trautscholdi |
But Deshayesitidae are not the only specimens found here. The vast array of heteromorphic ammonites — the Ancyloceratidae, inhabitants of relatively deep basins, has made it possible to propose a new scheme of ammonoid zonation in the lower Aptian epipelagic deposits of the Russian plate.
Many of the identified ancyloceratids were established here for the first time. The analysis of coexisting deshayesitids and heteromorphs enables a correlation of stratigraphic schemes for the monomorphic Deshayesitidae and heteromorphic Ancyloceratidae.
The described generic taxa and species are Volgoceratoides I. Michailova et Baraboshkin, gen. nov., V. schilovkensis I. Michailova et Baraboshkin, sp. nov., Koeneniceras I. Michailova et Baraboshkin, gen. nov., K. tenuiplicatum (von Koenen, 1902), K. rareplicatum I. Michailova et Baraboshkin, sp. nov.
In some sections of the Saratov Volga area, specifically in the central part of the Russian Platform, we find both offshore and nearshore lithofacies of the epicontinental Middle Russian Sea. Here we see simultaneous changes in ammonite and belemnite successions that speak to an environmental shift. The significant influence of anoxic events on faunal turnovers in marine communities is well-established. However, many studies are focused on the impact of anoxic conditions on benthic organisms, not on the hunter-gatherers living higher up in the sea column and food chain. For this reason, coeval changes in pelagic cephalopod assemblages remain relatively poorly studied and marginally understood.
Belemnites, represented by the late members of the family Oxyteuthididae, are common in the interval directly preceding the anoxic event, but totally disappear with the onset of the black shale deposition. We see a reduction in the shell size of the Deshayesites ammonites across the mudstone – black shale boundary (maximum shell diameter of adults reduces from ∼20 cm to 7–8 cm).
Some other ammonites become numerous (Sinzovia) within the black shale interval or show the first occurrence in it (Koeneniceras and Volgoceratoides). The diminishing of Deshayesites shell size during the early Aptian OAE may have been caused by palaeoenvironmental factors such as progressive warming and regional input of brackish water.
The significant influence of anoxic events on faunal turnovers in marine communities is well-established. However, many studies are focused on the impact of anoxic conditions on benthic organisms, not on the hunter-gatherers living higher up in the sea column. This means that coeval changes in pelagic cephalopod assemblages remain relatively poorly understood.
Photo: Jaubertites (Audouliceras) renauxianum (d'Orbigny, 1842) collection of José Juárez Ruiz.
Photo: Deshayesites volgensis (Sasonova, 1958), and Aconeceras (Sinzovia) trautscholdi (Sinzow. 1870) collections of Emil Black. The diameter on the Deshayesites shown here is 70 mm.
Rogov, Mikhail & Shchepetova, Elena & Ippolitov, Alexei & Seltser, Vladimir & Mironenko, Aleksandr & Pokrovsky, Boris & Desai, Bhawanisingh. (2019). Response of cephalopod communities on abrupt environmental changes during the early Aptian OAE1a in the Middle Russian Sea. Cretaceous Research. 10.1016/j.cretres.2019.01.007.
E. Yu. Baraboshkin and I. A. Mikhailova. New Stratigraphic Scheme of the Lower Aptian in the Volga River Middle Courses. Stratigraphy arid Geological Correlation, Vol 10, No 6, 2002, pp 603-626 Translated from Stratigrafiy a Geologicheskaya Korrelyatsiya, Vol 10, No 6, 2002, pp 82-105
Friday, 26 June 2020
HETTANGIAN: TETHYAN AFFINITY
Thursday, 25 June 2020
EXPLORING THE GSC COLLECTIONS
Wednesday, 24 June 2020
NORTH AMERICAN MIDDLE TRIASSIC AMMONOIDS
Tuesday, 23 June 2020
NAPPING KOALA
Monday, 22 June 2020
POKEY TACHYCLOSSIDAE
Echidnas are sometimes called spiny anteaters and belong in the family Tachyglossidae (Gill, 1872). They are monotremes, an order of egg-laying mammals.
There are four species of echidnas living today. They, along with the platypus, are the only living mammals who lay eggs and the only surviving members of the order Monotremata.
Superficially, they resemble the anteaters of South America and other spiny mammals like porcupines and adorable hedgehogs. They are usually a mix of brown, black and cream in colour. While rare, there have been several reported cases of albino echidnas, their eyes pink and their spines white. Echidnas have long, slender snouts that act as both nose and mouth for these cuties. The Giant Echidna we see in the fossil record had beaks more than double this size.
Like the platypus, they are equipped with electro sensors, but while the platypus has 40,000 electroreceptors on its bill, the long-beaked echidna has only 2,000. The short-beaked echidna, which lives in a drier environment, has no more than 400 at the tip of its snout.
Echidnas evolved between 20 and 50 million years ago, descending from a platypus-like monotreme. Their ancestors were aquatic, but echidnas have adapted to life on land. Today, they weigh in at about 7 kg today but back in the Pleistocene, they were much larger. The Giant Echnida, Megalibwilia ramsayi was about 10% larger at 10 kg and Zaglossus hacketti was a whopping 30 kg.
Fossil remains are relatively rare and sadly, incomplete, but they tell us potentially two other species of Echidna thriving in the Pleistocene. We also find Robust Echidna, Zaglossus robustus, in slightly older Miocene aged outcrops in a goldmine in Australia. The Giant Echnida's we find in the fossil record are relatives of the Long-Beaked Echidnas who live in New Guinea today.
Sunday, 21 June 2020
INUKSUK: STONE SENTINELS
These rocky sentinels stand as helpful reference markers for navigation.
Translated from Inuktitut, the word inuksuk means that which acts in the capacity of a human, combining inuk or person and suk, to substitute.