Tag Archive for 'Embryo'

Reconstruction of Qianlong shouhu’s eggs. Image credit: NICE Vistudio.

Eggs of Earliest Dinosaurs Were Leathery, Fossils Show

Nov 13, 2023 by Enrico de Lazaro

Paleontologists in China have unearthed and examined three adult skeletons and five clutches of embryo-containing eggs of Qianlong shouhu, a previously...

Larva of Hemidactylium scutatum, a species of lungless salamander native to eastern North America. Image credit: Zachary R. Lewis.

Lungless Salamanders Develop Lungs as Embryos, New Study Confirms

Aug 18, 2022 by News Staff

In a new study published this week in the journal Science Advances, scientists used morphological, molecular, and experimental approaches to examine members...

Embryological series of Japanese quail (Coturnix coturnix japonica) showing the transition from ancestral to derived pelvic states across avian prehatching ontogeny: (a) pelvic reconstructions along the evolutionary transition to living birds; note that pelves are shown as examples of character states and are not in one-to-one correspondence with ontogenetic stages; (b) during ontogeny, the ilium extends first posteriorly and then anteriorly, the pubis retroverts, the tail becomes relatively reduced and a transient pubic boot appears at intermediate ontogenetic stages; (c) the CFL (M. caudofemoralis longus homologue) is large during early ontogenetic stages; the IF (M. iliofemoralis homologue) originates smaller and further back on the ilium before expanding anteriorly to the derived condition and never splits into two muscles as seen in the adult; and PIFE1+2 (Mm. puboischiofemoralis externus 1 et 2 homologues) fail to fully differentiate until after the pubis is retroverted; muscles that are not highlighted are in gray; (d) the derived pelvic spinal nerve arrangement in birds (top), with additional spinal nerves contributing to the sacral plexus and nerves in Coturnix embryos (bottom). Scale bars - 1 mm in (b and d), 2 mm in (c). Image credit: Griffin et al., doi: 10.1038/s41586-022-04982-w.

Study: Developing Bird Hip Bone Passes through Ancestral Dinosaurian Conditions

Aug 8, 2022 by News Staff

Living birds have bodies substantially modified from the ancestral reptilian condition. The bird pelvis (hip bone) in particular experienced major changes...

An artist’s reconstruction of the oviraptorosaur egg and embryo from the Hekou Formation, Ganzhou, Jiangxi province, southern China. Image credit: Julius Csotonyi.

Paleontologists Find Exceptionally Preserved Embryo inside 70-Million-Year-Old Dinosaur Egg

Dec 22, 2021 by News Staff

The fossilized dinosaur egg from the Hekou Formation, Ganzhou, Jiangxi province, southern China, is elongate ovoid in shape with dimensions of 16.7 cm...

Colombelli-Négrel et al. demonstrate a capacity to perceive and learn to recognize sounds in ovo, as evidenced by habituation, even in bird species that were previously assumed to have little, if any, vocal production learning. Image credit: Barbara Fraatz.

Avian Vocal Learning Begins Before Birth, Study Says

Sep 7, 2021 by News Staff

An international team of scientists led by Flinders University has found evidence of prenatal auditory learning in embryos of three vocal learning species...

An artist’s impression of baby nanhsiungchelyid turtles. Image credit: Masato Hattori.

80-Million-Year-Old Turtle Egg with Embryonic Remains Found in China

Aug 24, 2021 by Sergio Prostak

The new specimen from the Upper Cretaceous Xiaguan Formation in the Chinese province of Henan is one of the few known fossilized turtle eggs containing...

An attentive oviraptorid theropod dinosaur broods its nest of blue-green eggs while its mate looks on in what is now Jiangxi Province of southern China some 70 million years ago. Image credit: Zhao Chuang.

Paleontologists Find Remains of Oviraptorid Dinosaur and Embryo-Bearing Egg Clutch

Mar 10, 2021 by News Staff

Paleontologists in China have discovered what they say is the first non-avialan dinosaur fossil known to preserve an adult skeleton atop an egg clutch...

Magnified perspective of the titanosaurian embryonic skull with the preorbital and orbital region in left lateral view. Image credit: Kundrat et al, doi: 10.1016/j.cub.2020.07.091.

Paleontologists Find Perfectly Preserved Embryo inside 80-Million-Year-Old Titanosaurian Egg

Aug 31, 2020 by News Staff

Paleontologists recently found well-preserved dinosaur eggs in an enormous nesting ground of titanosaurian sauropod dinosaurs that lived about 80 million...

Crawford et al demonstrated that squid genes can be efficiently disrupted using the CRISPR-Cas9 system. Image credit: Crawford et al, doi: 10.1016/j.cub.2020.06.099.

Scientists Create Transparent Squid Using CRISPR-Cas9 Technology

Aug 3, 2020 by News Staff

A team of researchers from the Marine Biological Laboratory, Harvard University and St. Mary’s College of Maryland has demonstrated efficient gene knockout...

The clutch of Massospondylus carinatus eggs. Image credit: Brett Eloff.

Scientists Use X-rays to Peer inside Fossilized Dinosaur Eggs

Apr 10, 2020 by Enrico de Lazaro

Powerful X-ray beams at the European Synchrotron in France allowed an international team of researchers to study some of the world’s oldest and well-preserved...

Yin et al use X-ray microtomography to show that the 609-million-year-old Caveasphaera develops within an envelope by cell division, ingression, detachment, and polar aggregation in a manner analogous to gastrulation; together with evidence of functional cell adhesion and development within an envelope, this is suggestive of a holozoan affinity. The image shows a life cycle of Caveasphaera and a simplified phylogenetic tree of Holozoa. Image credit: Yin et al, doi: 10.1016/j.cub.2019.10.057.

Animal-Like Embryos Evolved Long Before Complex Animals, Scientists Say

Nov 28, 2019 by News Staff

Complex animals evolved from single-celled ancestors, before diversifying into 30-40 distinct anatomical designs. When and how this major evolutionary...

Dorsal view of the left hand of a 10-week old human embryo. The dorsometacarpales are highlighted: these muscles are present in adults of many other limbed animals, while in humans they normally disappear or become fused with other muscles before birth. Image credit: Diogo et al, doi: 10.1242/dev.180349.

Human Embryos Have ‘Lizard-Like’ Limb Muscles: Study

Oct 2, 2019 by News Staff

A new study, published in the journal Development, has confirmed the transient presence of atavistic muscles — present in our ancestors, but normally...

Study: Pterosaurs Had Remarkable Ability to Fly from Birth

Jun 12, 2019 by News Staff

Pterosaurs were winged flying reptiles that lived at the same time as dinosaurs, between 210 million and 65 million years ago. Previously, they were thought...

A nesting cassowary-like dinosaur named Beibeilong sinensis in the act of incubating eggs. Image credit: Zhao Chuang.

Beibeilong sinensis: Paleontologists Identify New Species of Cassowary-Like Dinosaur

May 10, 2017 by News Staff

A team of paleontologists from Canada, China, the United States and Slovak Republic has identified a partial clutch of large dinosaur eggs with a closely...

Herds of female titanosaurs gathered at traditional nesting grounds 80 million years ago in what is now Patagonia, Argentina. Image credit: Luis Rey / Yale University.

Eggs of Non-Avian Dinosaurs Took 3-6 Months to Hatch

Jan 3, 2017 by News Staff

Non-avian dinosaur eggs took a long time to hatch — between 3 and 6 months, according to new research on the teeth of fossilized dinosaur embryos. Herds...

Oldest Reptile Embryos Discovered

Apr 12, 2012 by Sergio Prostak

An international team of paleontologists has unearthed the oldest known fossil reptile embryos dating back about 280 million years. An artist’s reconstruction...