Restoration of the extinct, tree-living, vegetarian early Cretaceous bird Jeholornis eating leaves. Credit: IVPP
New findings from the analysis of a 120-million-year-old fossil skeleton of the extinct bird Jeholornis, unearthed from northeastern China, present the earliest known evidence of leaf-eating birds, marking the earliest known development of arboreal plant-eating among birds.
The pheasant-sized Jeholornis, a member of the 2nd most primitive lineage of recognized birds, has teeth and a long bony tail like its predatory, feathered dinosaur relatives. Tiny analysis of the fossilized residues in the stomach of this juvenile, arboreal (tree-living) bird shows that Jeholornis was not a predator. It had consumed tree leaves from a group of blooming plants called magnoliids that includes the living magnolia, cinnamon, and avocado trees.
The study, published in Nature Communications on July 28, was carried out by researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences and their partners.
Close relationships in between birds and blooming plants (angiosperms) are prevalent today and include birds pollinating angiosperm flowers, consuming their fruits, and distributing their seeds. Nevertheless, the fossil record has actually not offered much proof about the evolutionary origins of these close environmental relationships.
The presence of gizzard stones (gastroliths) utilized to grind plant parts during food digestion in the stomach areas of fossil skeletons allow paleontologists to identify that the diet plans of some early birds included plant parts. More direct evidence of plants in the diet plan of the earliest lineages of birds comes from other fossil skeletons of Jeholornis with fossilized fruit and seeds protected in their digestive system.
The 120-million-year-old fossil skeleton with feathers of the juvenile early riser Jeholornis from China, showing some tiny fossil phytolith remains of its last meal of leaves from magnoliid trees that were extracted from the remains of the birds stomach, in comparison with phytoliths from living magnoliid trees. Credit: IVPP
” The fossils from the Jehol Biota in China reveal us that really early in bird evolution they switched from predatory behaviors to utilizing their wings to fly into trees so they might consume the fruits, seeds, and leaves of plants thus numerous types do today,” stated Dr. LI Zhiheng from IVPP, matching author of the research study.
To better understand early riser diets, this worldwide group of scientists looked for the tiny fossilized residues of plants within the remains of the ancient stomach contents inside the bird skeleton, a method not attempted before. They aimed to discover phytoliths, which are stiff tiny structures made of opaline silica (silicon dioxide) produced by plants within and in between their cells.
The researchers sampled the fossilized stomach location around the gastroliths to attempt to find the phytolith stays of long-decayed plants. They recuperated hundreds of phytoliths after processing the tiny samples with acid and other chemicals to remove nearly whatever that is not a phytolith.
” After contrast with over 4,000 type of modern phytoliths, we can see that the majority of the identifiable fossil phytoliths from the stomach originated from the leaves of magnoliids,” stated Dr. Wu Yan from IVPP, first author of the research study. Similar samples of the rock surrounding the fossil bird skeleton produced no phytolith stays at all, assisting to verify that the recuperated phytoliths represent part of the birds diet.
To further support their hypothesis of leaf-eating in this early riser, the paleontologists likewise compared the lower jaw of this bird to living birds with a wide variety of diet plans. Coauthor Dr. Hu Han from Oxford University stated, “A more comprehensive analytical analysis of the three-dimensional shape of the lower jaw of Jeholornis shows similarities to the shapes of living birds that eat primarily plants consisting of the living leaf expert, the hoatzin from tropical forests in South America.”
Flowering plants are key to living bird variety due to the fact that numerous use nectar and numerous plant parts to fuel their energetic flight and quick growth, and many brilliant plume colors originate from eating plants.
” As we can see with this extinct, vegetarian, tree-living bird, the evolution of birds has been connected to blooming plants for over 100 million years with fruits, seeds, and even leaves working as main dishes on the bird menu starting initially when birds still had teeth and long, bony dinosaurian tails,” stated Dr. Thomas Stidham from the IVPP, co-author of the study.
Recommendation: “Intra-gastric phytoliths provide evidence for folivory in basal avialans of the Early Cretaceous Jehol Biota” by Yan Wu, Yong Ge, Han Hu, Thomas A. Stidham, Zhiheng Li, Alida M. Bailleul and Zhonghe Zhou, 28 July 2023, Nature Communications.DOI: 10.1038/ s41467-023-40311-z.
