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In 1968 Shirley Chisholm became the first Black woman elected to the United States Congress. In 1972 she launched a campaign for the Democratic presidential nomination, breaking another political barrier.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
Sauriurae (meaning "lizard tails" in Greek) is a now-deprecated subclass of birds created by Ernst Haeckel in 1866. It was intended to include Archaeopteryx and distinguish it from all other birds then known, which he grouped in the sister-group Ornithurae ("bird tails"). The distinction Haeckel referred to in this name is that Archaeopteryx possesses a long, reptile-like tail, while all other birds known to him had short tails with few vertebrae, fused at the end into a pygostyle.[1] The unit was not much referred to, and when Hans Friedrich Gadow in 1893 erected Archaeornithes for basically the same fossils, this became the common name for the early reptile-like grade of birds.
Ji Qiang and Larry Martin have continued to refer to the Sauriurae as a valid natural group.[2] However, researchers like Jacques Gauthier (2001)[3] and Julia Clarke (2002)[4] have found that fossils found after Haeckel's time have bridged the gap between long and short-tailed Avialae. In their view, any grouping of avialans with long tails must exclude some of their descendants—making Sauriurae a paraphyletic and, thus, an invalid group under current systems of phylogenetic nomenclature.
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Sauriurae (meaning "lizard tails" in Greek) is a now-deprecated subclass of birds created by Ernst Haeckel in 1866. It was intended to include Archaeopteryx and distinguish it from all other birds then known, which he grouped in the sister-group Ornithurae ("bird tails"). The distinction Haeckel referred to in this name is that Archaeopteryx possesses a long, reptile-like tail, while all other birds known to him had short tails with few vertebrae, fused at the end into a pygostyle. The unit was not much referred to, and when Hans Friedrich Gadow in 1893 erected Archaeornithes for basically the same fossils, this became the common name for the early reptile-like grade of birds. Ji Qiang and Larry Martin have continued to refer to the Sauriurae as a valid natural group. However, researchers like Jacques Gauthier (2001) and Julia Clarke (2002) have found that fossils found after Haeckel's time have bridged the gap between long and short-tailed Avialae. In their view, any grouping of avialans with long tails must exclude some of their descendants—making Sauriurae a paraphyletic and, thus, an invalid group under current systems of phylogenetic nomenclature.
Odontornithes is an obsolete and disused taxonomic term proposed by Othniel Charles Marsh for birds possessing teeth, notably the genera Hesperornis and Ichthyornis from the Cretaceous deposits of Kansas. In 1875 Marsh divided this "subclass" into Odontolcae, with the teeth standing in grooves, and Odontotormae, with the teeth in separate alveoles or sockets. In his 1880 work, Odontornithes: A monograph on the extinct toothed birds of North America, he added the Sauriurae, represented by Archaeopteryx, as a third order. The resulting classification was paraphyletic, not accurately resolving evolutionary relationships, and so it has been abandoned by most modern scientists, though at least one 21st-century paper re-used the concept under the older name Odontoholomorphae (coined by Stejneger, 1885). Étienne Geoffroy Saint-Hilaire stated in 1821 that he had found a considerable number of tooth buds in the upper and lower jaws of Palaeornis torquatus, the rose-ringed parakeet. Émile Blanchard felt justified in recognizing flakes of dentine. However, M. Braun and especially P. Fraisse showed later that the structures in question are of the same kind as the well-known serrated "teeth" of the bill of anserine birds. In fact the papillae observed in the embryonic birds are the soft cutaneous extensions into the surrounding horny sheath of the bill, comparable to the well-known nutritive papillae in a horse's hoof. They are easily exposed in the well-macerated lower jaw of a parrot, after removal of the horny sheath. Occasionally calcification occurs in or around these papillae, as it does regularly in the egg tooth of the embryos of all birds. The best known of the "Odontornithes" are Hesperornis regalis, standing about 3 ft (0.9 m) high, the somewhat taller H. crassipes, and Ichthyornis dispar. Hesperornis looked somewhat similar to a loon, while Ichthyornis was quite similar to a gull or petrel. However, they were entirely distinct groups of birds and merely shared with modern birds some distant ancestry in the Early Cretaceous. The Hesperornis lineage may have derived even sooner or possibly independently from the ancestors of modern birds.
Deinonychosauria is a clade of paravian dinosaurs that lived from the Late Jurassic to the Late Cretaceous periods. Fossils have been found across the globe in North America, Europe, Africa, Asia, South America, and Antarctica, with fossilized teeth giving credence to the possibility that they inhabited Australia as well. This group of dinosaurs are known for their sickle-shaped toe claws and features in the shoulder bones. Deinonychosauria is commonly defined as all dinosaurs more closely related to dromaeosaurids (such as Deinonychus antirrhopus) than to birds (such as Passer domesticus). It traditionally includes the families Dromaeosauridae and Troodontidae, which each possess enlarged "sickle claws". Troodontids may instead be closer to birds than to dromaeosaurids, however, so they would lie outside Deinonychosauria under that hypothesis. This would also render Deinonychosauria equivalent to Dromaeosauridae, under a broad definition of the family. As the structure of the paravian family is still undergoing debate, the components of Deinonychosauria is unstable beyond dromaeosaurids.
Therizinosaurus ( ; meaning 'scythe lizard') is a genus of very large therizinosaurid dinosaurs that lived in the Maastrichtian age during the Late Cretaceous period in what is now Asia roughly 69-66 million years ago. It contains a single species, Therizinosaurus cheloniformis, known from the fossiliferous Nemegt Formation. The first remains of Therizinosaurus were found in 1948 by a Mongolian field expedition in the Gobi Desert and later described by Evgeny Maleev in 1954. The genus is only known from a few bones, including gigantic manual unguals (claw bones), from which it gets its name, and additional findings comprising fore and hindlimb elements that were discovered from the 1960s through the 1980s. Therizinosaurus was a colossal therizinosaurid that could grow up to 9–10 m (30–33 ft) long and 4–5 m (13–16 ft) tall, and weigh possibly over 5 t (5.5 short tons). Like other therizinosaurids, it would have been a slow-moving, long-necked, high browser equipped with a rhamphotheca (beak) and a wide torso for food processing. Its forelimbs were particularly robust and had three fingers that bore unguals which, unlike other relatives, were very stiffened, elongated, and only had significant curvatures at the tips. Therizinosaurus had the longest known manual unguals of any land animal, reaching above 50 cm (20 in) in length. Its hindlimbs ended in four functionally weight-bearing toes differing from other theropod groups in which the first toe was reduced to a dewclaw and also resembling the very distantly related sauropodomorphs. It was one of the last and the largest representative of its unique group, the Therizinosauria (formerly known as Segnosauria; the segnosaurs). During and after its original description in 1954, Therizinosaurus had rather complex relationships due to the lack of complete specimens and relatives at the time. Maleev thought the remains of Therizinosaurus to belong to a large turtle-like reptile, and also named a separate family for the genus: Therizinosauridae. Later on, with the discovery of more complete relatives, Therizinosaurus and kin were thought to represent some kind of Late Cretaceous sauropodomorphs or transitional ornithischians, even though at some point it was suggested that it may have been a theropod. After years of taxonomic debate, nevertheless, they are now placed in one of the major dinosaur clades, Theropoda, specifically as maniraptorans. Therizinosaurus is widely recovered within Therizinosauridae by most analyses. The unusual arms and body anatomy (extrapolated after relatives) of Therizinosaurus have been cited as an example of convergent evolution with chalicotheriines and other primarily herbivorous mammals like ground sloths, suggesting similar feeding habits. The elongated hand claws of Therizinosaurus were possibly more efficient at pulling vegetation within reach than being used for active attack or defense because it has been believed they would have been relatively fragile. However, Its arms were found to have been particularly resistant to stress, which suggests a robust and versatile use of these limbs ranging from both foraging and self defense. Therizinosaurus was a very tall animal, likely having a reduced competition over the foliage in its habitat and rivalling predators like the tyrannosaurid Tarbosaurus in size.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →The Greenwood District.
